diff --git a/chain/gen/gen.go b/chain/gen/gen.go
index 067ea6ef0..7cc472273 100644
--- a/chain/gen/gen.go
+++ b/chain/gen/gen.go
@@ -32,7 +32,7 @@ import (
 
 var log = logging.Logger("gen")
 
-const msgsPerBlock = 20
+const msgsPerBlock = 2
 
 type ChainGen struct {
 	accounts []address.Address
@@ -260,6 +260,8 @@ func (cg *ChainGen) NextTipSet() (*MinedTipSet, error) {
 		return nil, err
 	}
 
+	base := cg.curTipset.TipSet()
+
 	for len(blks) == 0 {
 		for i, m := range cg.miners {
 			proof, t, err := cg.nextBlockProof(context.TODO(), m, ticketSets[i])
@@ -269,7 +271,7 @@ func (cg *ChainGen) NextTipSet() (*MinedTipSet, error) {
 
 			ticketSets[i] = append(ticketSets[i], t)
 			if proof != nil {
-				fblk, err := cg.makeBlock(m, proof, ticketSets[i], msgs)
+				fblk, err := cg.makeBlock(base, m, proof, ticketSets[i], msgs)
 				if err != nil {
 					return nil, xerrors.Errorf("making a block for next tipset failed: %w", err)
 				}
@@ -284,6 +286,7 @@ func (cg *ChainGen) NextTipSet() (*MinedTipSet, error) {
 	}
 
 	cg.curTipset = store.NewFullTipSet(blks)
+	fmt.Printf("Mined tipset %s (%d) on top of %s (%d)\n", cg.curTipset.Cids(), cg.curTipset.TipSet().Height(), base.Cids(), base.Height())
 
 	return &MinedTipSet{
 		TipSet:   cg.curTipset,
@@ -291,9 +294,7 @@ func (cg *ChainGen) NextTipSet() (*MinedTipSet, error) {
 	}, nil
 }
 
-func (cg *ChainGen) makeBlock(m address.Address, eproof types.ElectionProof, tickets []*types.Ticket, msgs []*types.SignedMessage) (*types.FullBlock, error) {
-
-	parents := cg.curTipset.TipSet()
+func (cg *ChainGen) makeBlock(parents *types.TipSet, m address.Address, eproof types.ElectionProof, tickets []*types.Ticket, msgs []*types.SignedMessage) (*types.FullBlock, error) {
 
 	ts := parents.MinTimestamp() + (uint64(len(tickets)) * build.BlockDelay)
 
diff --git a/chain/store/store.go b/chain/store/store.go
index 5115bc129..aac5cd993 100644
--- a/chain/store/store.go
+++ b/chain/store/store.go
@@ -179,7 +179,13 @@ func (cs *ChainStore) PutTipSet(ts *FullTipSet) error {
 		}
 	}
 
-	if err := cs.MaybeTakeHeavierTipSet(ts.TipSet()); err != nil {
+	expanded, err := cs.expandTipset(ts.TipSet().Blocks()[0])
+	if err != nil {
+		return xerrors.Errorf("errored while expanding tipset: %w", err)
+	}
+	fmt.Printf("expanded %s into %s\n", ts.TipSet().Cids(), expanded.Cids())
+
+	if err := cs.MaybeTakeHeavierTipSet(expanded); err != nil {
 		return errors.Wrap(err, "MaybeTakeHeavierTipSet failed in PutTipSet")
 	}
 	return nil
diff --git a/chain/sync.go b/chain/sync.go
index ee9a69cd4..755b10e58 100644
--- a/chain/sync.go
+++ b/chain/sync.go
@@ -510,11 +510,6 @@ loop:
 		// NB: GetBlocks validates that the blocks are in-fact the ones we
 		// requested, and that they are correctly linked to eachother. It does
 		// not validate any state transitions
-		fmt.Println("Get blocks")
-		if len(at) == 0 {
-			fmt.Println("Weird situation, about to request blocks with empty tipset")
-			fmt.Println("info: ", len(blockSet), blockSet[len(blockSet)-1].Height(), untilHeight)
-		}
 		blks, err := syncer.Bsync.GetBlocks(context.TODO(), at, 10)
 		if err != nil {
 			// Most likely our peers aren't fully synced yet, but forwarded
@@ -537,13 +532,21 @@ loop:
 			blockSet = append(blockSet, b)
 		}
 
-		fmt.Println("AT CHILD: ", blks[len(blks)-1].Height())
 		at = blks[len(blks)-1].Parents()
 	}
 
+	// We have now ascertained that this is *not* a 'fast forward'
 	if !types.CidArrsEqual(blockSet[len(blockSet)-1].Parents(), to.Cids()) {
+		last := blockSet[len(blockSet)-1]
+		if types.CidArrsEqual(last.Parents(), to.Parents()) {
+			// common case: receiving a block thats potentially part of the same tipset as our best block
+			return blockSet, nil
+		}
+
 		// TODO: handle the case where we are on a fork and its not a simple fast forward
-		return nil, xerrors.Errorf("synced header chain does not link to our best block")
+		// need to walk back to either a common ancestor, or until we hit the fork length threshold.
+		return nil, xerrors.Errorf("(fork detected) synced header chain (%s - %d) does not link to our best block (%s - %d)", from.Cids(), from.Height(), to.Cids(), to.Height())
+
 	}
 
 	return blockSet, nil
diff --git a/chain/sync_test.go b/chain/sync_test.go
index 8a2e1b324..b81facd48 100644
--- a/chain/sync_test.go
+++ b/chain/sync_test.go
@@ -290,7 +290,6 @@ func TestSyncMining(t *testing.T) {
 	tu.compareSourceState(client)
 
 	for i := 0; i < 5; i++ {
-		fmt.Println("MINE A NEW BLOCK")
 		tu.mineNewBlock(0)
 		tu.waitUntilSync(0, client)
 		tu.compareSourceState(client)
diff --git a/chain/types/blockheader.go b/chain/types/blockheader.go
index 784764514..f5c078e6b 100644
--- a/chain/types/blockheader.go
+++ b/chain/types/blockheader.go
@@ -125,8 +125,15 @@ func CidArrsEqual(a, b []cid.Cid) bool {
 	if len(a) != len(b) {
 		return false
 	}
-	for i, v := range a {
-		if b[i] != v {
+
+	// order ignoring compare...
+	s := make(map[cid.Cid]bool)
+	for _, c := range a {
+		s[c] = true
+	}
+
+	for _, c := range b {
+		if !s[c] {
 			return false
 		}
 	}
diff --git a/chain/types/tipset.go b/chain/types/tipset.go
index 2d763650a..00110dd3e 100644
--- a/chain/types/tipset.go
+++ b/chain/types/tipset.go
@@ -46,6 +46,14 @@ func (ts *TipSet) UnmarshalJSON(b []byte) error {
 }
 
 func NewTipSet(blks []*BlockHeader) (*TipSet, error) {
+	/*
+		sort.Slice(blks, func(i, j int) bool {
+			a := blks[i].LastTicket()
+			b := blks[j].LastTicket()
+			return bytes.Compare(a.VDFResult, b.VDFResult) < 0
+		})
+	*/
+
 	var ts TipSet
 	ts.cids = []cid.Cid{blks[0].Cid()}
 	ts.blks = blks
diff --git a/go.mod b/go.mod
index 18cd19baf..3d74702c5 100644
--- a/go.mod
+++ b/go.mod
@@ -15,7 +15,7 @@ require (
 	github.com/gorilla/websocket v1.4.0
 	github.com/ipfs/go-bitswap v0.1.8
 	github.com/ipfs/go-block-format v0.0.2
-	github.com/ipfs/go-blockservice v0.1.2
+	github.com/ipfs/go-blockservice v0.1.3-0.20190908200855-f22eea50656c
 	github.com/ipfs/go-car v0.0.0-20190823083746-79984a8632b4
 	github.com/ipfs/go-cid v0.0.3
 	github.com/ipfs/go-datastore v0.1.0
diff --git a/go.sum b/go.sum
index c0618ce4f..0e480d313 100644
--- a/go.sum
+++ b/go.sum
@@ -148,6 +148,8 @@ github.com/ipfs/go-block-format v0.0.2/go.mod h1:AWR46JfpcObNfg3ok2JHDUfdiHRgWhJ
 github.com/ipfs/go-blockservice v0.1.0/go.mod h1:hzmMScl1kXHg3M2BjTymbVPjv627N7sYcvYaKbop39M=
 github.com/ipfs/go-blockservice v0.1.2 h1:fqFeeu1EG0lGVrqUo+BVJv7LZV31I4ZsyNthCOMAJRc=
 github.com/ipfs/go-blockservice v0.1.2/go.mod h1:t+411r7psEUhLueM8C7aPA7cxCclv4O3VsUVxt9kz2I=
+github.com/ipfs/go-blockservice v0.1.3-0.20190908200855-f22eea50656c h1:lN5IQA07VtLiTLAp/Scezp1ljFhXErC6yq4O1cu+yJ0=
+github.com/ipfs/go-blockservice v0.1.3-0.20190908200855-f22eea50656c/go.mod h1:t+411r7psEUhLueM8C7aPA7cxCclv4O3VsUVxt9kz2I=
 github.com/ipfs/go-car v0.0.0-20190823083746-79984a8632b4 h1:qYLz/x/d1SOiiFGS8dwCBCFJ5Oh64Y8HMBrS+MbaU8c=
 github.com/ipfs/go-car v0.0.0-20190823083746-79984a8632b4/go.mod h1:NSSM0pxlhej9rSFXQmB/lDru7TYNoDjKgmvqzlsd06Y=
 github.com/ipfs/go-cid v0.0.1/go.mod h1:GHWU/WuQdMPmIosc4Yn1bcCT7dSeX4lBafM7iqUPQvM=