diff --git a/chain/chain_manager.go b/chain/chain_manager.go
index 11e16fa7d2..335e68b5cc 100644
--- a/chain/chain_manager.go
+++ b/chain/chain_manager.go
@@ -196,7 +196,6 @@ func (self *ChainManager) GetBlock(hash []byte) *types.Block {
 				}
 			}
 		}
-
 		return nil
 	}
 
@@ -229,7 +228,8 @@ func (self *ChainManager) CalcTotalDiff(block *types.Block) (*big.Int, error) {
 		return nil, fmt.Errorf("Unable to calculate total diff without known parent %x", block.PrevHash)
 	}
 
-	parentTd := parent.BlockInfo().TD
+	//parentTd := parent.BlockInfo().TD
+	parentTd := self.BlockInfo(parent).TD
 
 	uncleDiff := new(big.Int)
 	for _, uncle := range block.Uncles {
@@ -246,8 +246,20 @@ func (self *ChainManager) CalcTotalDiff(block *types.Block) (*big.Int, error) {
 func (bc *ChainManager) BlockInfo(block *types.Block) types.BlockInfo {
 	bi := types.BlockInfo{}
 	data, _ := ethutil.Config.Db.Get(append(block.Hash(), []byte("Info")...))
+	if len(data) == 0 {
+		if bc.workingChain != nil {
+			// Check the temp chain
+			for e := bc.workingChain.Front(); e != nil; e = e.Next() {
+				l := e.Value.(*link)
+				b := l.Block
+				if bytes.Compare(b.Hash(), block.Hash()) == 0 {
+					bi = types.BlockInfo{Number: b.Number.Uint64(), Hash: b.Hash(), Parent: b.PrevHash, TD: l.Td}
+					return bi
+				}
+			}
+		}
+	}
 	bi.RlpDecode(data)
-
 	return bi
 }
 
@@ -275,8 +287,10 @@ func (self *ChainManager) InsertChain(chain *BlockChain, call func(*types.Block,
 	for e := chain.Front(); e != nil; e = e.Next() {
 		link := e.Value.(*link)
 
-		self.add(link.Block)
+		// must set TD before adding as
+		// add calls writeBlockInfo which writes the most recent TD
 		self.SetTotalDifficulty(link.Td)
+		self.add(link.Block)
 
 		call(link.Block, link.Messages)
 	}
diff --git a/chain/chain_manager_test.go b/chain/chain_manager_test.go
index 1849c48f5e..2745553ea7 100644
--- a/chain/chain_manager_test.go
+++ b/chain/chain_manager_test.go
@@ -16,22 +16,15 @@ import (
 	"github.com/ethereum/go-ethereum/wire"
 )
 
-// In these tests, TD = block.Number
-var TD *big.Int
-
 func init() {
+	initDB()
+}
+
+func initDB() {
 	ethutil.ReadConfig(".ethtest", "/tmp/ethtest", "")
 	ethutil.Config.Db, _ = ethdb.NewMemDatabase()
 }
 
-type fakeproc struct {
-}
-
-func (self fakeproc) ProcessWithParent(a, b *types.Block) (*big.Int, state.Messages, error) {
-	TD = new(big.Int).Add(TD, big.NewInt(1))
-	return TD, nil, nil
-}
-
 // So we can generate blocks easily
 type fakePow struct{}
 
@@ -56,61 +49,120 @@ func (e *fakeEth) ClientIdentity() wire.ClientIdentity                { return n
 func (e *fakeEth) Db() ethutil.Database                               { return nil }
 func (e *fakeEth) EventMux() *event.TypeMux                           { return nil }
 
-func makechain(cman *ChainManager, max int) *BlockChain {
-	blocks := make(types.Blocks, max)
-	for i := 0; i < max; i++ {
-		addr := ethutil.LeftPadBytes([]byte{byte(i)}, 20)
-		block := cman.NewBlock(addr)
-		if i != 0 {
-			cman.CurrentBlock = blocks[i-1]
-		}
-		blocks[i] = block
-	}
-	return NewChain(blocks)
+func newBlockFromParent(addr []byte, parent *types.Block) *types.Block {
+	block := types.CreateBlock(
+		parent.Root(),
+		parent.Hash(),
+		addr,
+		ethutil.BigPow(2, 32),
+		nil,
+		"")
+	block.MinGasPrice = big.NewInt(10000000000000)
+	block.Difficulty = CalcDifficulty(block, parent)
+	block.Number = new(big.Int).Add(parent.Number, ethutil.Big1)
+	block.GasLimit = block.CalcGasLimit(parent)
+	return block
 }
 
-func makechain2(bman *BlockManager, max int) *BlockChain {
-	parent := bman.bc.CurrentBlock
+// Actually make a block by simulating what miner would do
+func makeblock(bman *BlockManager, parent *types.Block, i int) *types.Block {
+	addr := ethutil.LeftPadBytes([]byte{byte(i)}, 20)
+	block := newBlockFromParent(addr, parent)
+	cbase := block.State().GetOrNewStateObject(addr)
+	cbase.SetGasPool(block.CalcGasLimit(parent))
+	receipts, txs, _, _, _ := bman.ProcessTransactions(cbase, block.State(), block, block, types.Transactions{})
+	block.SetTransactions(txs)
+	block.SetReceipts(receipts)
+	bman.AccumelateRewards(block.State(), block, parent)
+	block.State().Update()
+	return block
+}
+
+// Make a chain with real blocks
+// Runs ProcessWithParent to get proper state roots
+func makechain(bman *BlockManager, parent *types.Block, max int) *BlockChain {
+	bman.bc.CurrentBlock = parent
+	bman.bc.LastBlockHash = parent.Hash()
 	blocks := make(types.Blocks, max)
+	var td *big.Int
 	for i := 0; i < max; i++ {
-		addr := ethutil.LeftPadBytes([]byte{byte(i)}, 20)
-		block := bman.bc.NewBlock(addr)
-		cbase := block.State().GetOrNewStateObject(addr)
-		cbase.SetGasPool(block.CalcGasLimit(parent))
-		receipts, txs, _, _, _ := bman.ProcessTransactions(cbase, block.State(), block, block, types.Transactions{})
-		block.SetTransactions(txs)
-		block.SetReceipts(receipts)
-
-		bman.AccumelateRewards(block.State(), block, parent)
-
-		block.State().Update()
-		lchain := NewChain(types.Blocks{block})
-		_, err := bman.bc.TestChain(lchain)
-		if err != nil {
-			fmt.Println("failed to run test chain!:", err)
-		}
-		bman.bc.InsertChain(lchain, func(block *types.Block, _ state.Messages) {})
-
+		block := makeblock(bman, parent, i)
+		// add the parent and its difficulty to the working chain
+		// so ProcessWithParent can access it
+		bman.bc.workingChain = NewChain(types.Blocks{parent})
+		bman.bc.workingChain.Back().Value.(*link).Td = td
+		td, _, _ = bman.bc.processor.ProcessWithParent(block, parent)
 		blocks[i] = block
 		parent = block
 	}
-	return NewChain(blocks)
+	lchain := NewChain(blocks)
+	return lchain
+}
+
+// Make a new canonical chain by running TestChain and InsertChain
+// on result of makechain
+func newCanonical(n int) (*BlockManager, error) {
+	bman := &BlockManager{bc: NewChainManager(), Pow: fakePow{}, eth: &fakeEth{}}
+	bman.bc.SetProcessor(bman)
+	parent := bman.bc.CurrentBlock
+	lchain := makechain(bman, parent, 5)
+
+	_, err := bman.bc.TestChain(lchain)
+	if err != nil {
+		return nil, err
+	}
+	bman.bc.InsertChain(lchain, func(block *types.Block, _ state.Messages) {})
+	return bman, nil
+}
+
+// new chain manager without setLastBlock
+func newChainManager() *ChainManager {
+	bc := &ChainManager{}
+	bc.genesisBlock = types.NewBlockFromBytes(ethutil.Encode(Genesis))
+	bc.Reset()
+	return bc
+}
+
+func TestExtendCanonical(t *testing.T) {
+	initDB()
+	// make first chain starting from genesis
+	bman, err := newCanonical(5)
+	if err != nil {
+		t.Fatal("Could not make new canonical chain:", err)
+	}
+
+	// make second chain starting from end of first chain
+	bman2 := &BlockManager{bc: NewChainManager(), Pow: fakePow{}, eth: &fakeEth{}}
+	bman2.bc.SetProcessor(bman2)
+	parent := bman.bc.CurrentBlock
+	chainB := makechain(bman2, parent, 3)
+
+	// test second chain against first
+	td2, err := bman.bc.TestChain(chainB)
+	if err != nil && !IsTDError(err) {
+		t.Error("expected chainB not to give errors:", err)
+	}
+
+	if td2.Cmp(bman.bc.TD) <= 0 {
+		t.Error("expected chainB to have higher difficulty. Got", td2, "expected more than", bman.bc.TD)
+	}
 }
 
 func TestShorterFork(t *testing.T) {
-	cman := NewChainManager()
-	bman := &BlockManager{bc: cman, Pow: fakePow{}, eth: &fakeEth{}}
-	bman.bc.SetProcessor(bman)
+	initDB()
+	// make first chain starting from genesis
+	bman, err := newCanonical(5)
+	if err != nil {
+		t.Fatal("Could not make new canonical chain:", err)
+	}
 
-	makechain2(bman, 5)
-
-	cman2 := NewChainManager()
-	cman2.Reset() // so we don't end up with last block of cman1
-	bman2 := &BlockManager{bc: cman2, Pow: fakePow{}, eth: &fakeEth{}}
+	// make second, shorter chain, starting from genesis
+	bman2 := &BlockManager{bc: newChainManager(), Pow: fakePow{}, eth: &fakeEth{}}
 	bman2.bc.SetProcessor(bman2)
+	parent := bman2.bc.CurrentBlock
+	chainB := makechain(bman2, parent, 3)
 
-	chainB := makechain2(bman2, 3)
-
+	// test second chain against first
 	td2, err := bman.bc.TestChain(chainB)
 	if err != nil && !IsTDError(err) {
 		t.Error("expected chainB not to give errors:", err)
@@ -122,76 +174,88 @@ func TestShorterFork(t *testing.T) {
 }
 
 func TestLongerFork(t *testing.T) {
-	cman := NewChainManager()
-	cman.SetProcessor(fakeproc{})
-
-	TD = big.NewInt(1)
-	chainA := makechain(cman, 5)
-
-	TD = big.NewInt(1)
-	chainB := makechain(cman, 10)
-
-	td, err := cman.TestChain(chainA)
+	initDB()
+	// make first chain starting from genesis
+	bman, err := newCanonical(5)
 	if err != nil {
-		t.Error("unable to create new TD from chainA:", err)
+		t.Fatal("Could not make new canonical chain:", err)
 	}
-	cman.TD = td
 
-	_, err = cman.TestChain(chainB)
+	// make second, longer chain, starting from genesis
+	bman2 := &BlockManager{bc: newChainManager(), Pow: fakePow{}, eth: &fakeEth{}}
+	bman2.bc.SetProcessor(bman2)
+	parent := bman2.bc.CurrentBlock
+	chainB := makechain(bman2, parent, 10)
+
+	td, err := bman.bc.TestChain(chainB)
 	if err != nil {
 		t.Error("expected chainB not to give errors:", err)
 	}
+
+	if td.Cmp(bman.bc.TD) <= 0 {
+		t.Error("expected chainB to have higher difficulty. Got", td, "expected more than", bman.bc.TD)
+	}
 }
 
 func TestEqualFork(t *testing.T) {
-	cman := NewChainManager()
-	cman.SetProcessor(fakeproc{})
-
-	TD = big.NewInt(1)
-	chainA := makechain(cman, 5)
-
-	TD = big.NewInt(2)
-	chainB := makechain(cman, 5)
-
-	td, err := cman.TestChain(chainA)
+	initDB()
+	bman, err := newCanonical(5)
 	if err != nil {
-		t.Error("unable to create new TD from chainA:", err)
+		t.Fatal("Could not make new canonical chain:", err)
 	}
-	cman.TD = td
 
-	_, err = cman.TestChain(chainB)
-	if err != nil {
+	bman2 := &BlockManager{bc: newChainManager(), Pow: fakePow{}, eth: &fakeEth{}}
+	bman2.bc.SetProcessor(bman2)
+	parent := bman2.bc.CurrentBlock
+
+	chainB := makechain(bman2, parent, 5)
+
+	td, err := bman.bc.TestChain(chainB)
+	if err != nil && !IsTDError(err) {
 		t.Error("expected chainB not to give errors:", err)
 	}
+
+	if td.Cmp(bman.bc.TD) != 0 {
+		t.Error("expected chainB to have equal difficulty. Got", td, "expected less than", bman.bc.TD)
+	}
 }
 
 func TestBrokenChain(t *testing.T) {
-	cman := NewChainManager()
-	cman.SetProcessor(fakeproc{})
+	initDB()
+	bman, err := newCanonical(5)
+	if err != nil {
+		t.Fatal("Could not make new canonical chain:", err)
+	}
 
-	TD = big.NewInt(1)
-	chain := makechain(cman, 5)
-	chain.Remove(chain.Front())
+	bman2 := &BlockManager{bc: NewChainManager(), Pow: fakePow{}, eth: &fakeEth{}}
+	bman2.bc.SetProcessor(bman2)
+	parent := bman2.bc.CurrentBlock
 
-	_, err := cman.TestChain(chain)
+	chainB := makechain(bman2, parent, 5)
+	chainB.Remove(chainB.Front())
+
+	_, err = bman.bc.TestChain(chainB)
 	if err == nil {
 		t.Error("expected broken chain to return error")
 	}
 }
 
 func BenchmarkChainTesting(b *testing.B) {
+	initDB()
 	const chainlen = 1000
 
-	ethutil.ReadConfig(".ethtest", "/tmp/ethtest", "")
-	ethutil.Config.Db, _ = ethdb.NewMemDatabase()
+	bman, err := newCanonical(5)
+	if err != nil {
+		b.Fatal("Could not make new canonical chain:", err)
+	}
 
-	cman := NewChainManager()
-	cman.SetProcessor(fakeproc{})
+	bman2 := &BlockManager{bc: NewChainManager(), Pow: fakePow{}, eth: &fakeEth{}}
+	bman2.bc.SetProcessor(bman2)
+	parent := bman2.bc.CurrentBlock
 
-	TD = big.NewInt(1)
-	chain := makechain(cman, chainlen)
+	chain := makechain(bman2, parent, chainlen)
 
 	stime := time.Now()
-	cman.TestChain(chain)
+	bman.bc.TestChain(chain)
 	fmt.Println(chainlen, "took", time.Since(stime))
 }