diff --git a/chain/actors/actor_miner.go b/chain/actors/actor_miner.go
index a642beba0..46ab1b00e 100644
--- a/chain/actors/actor_miner.go
+++ b/chain/actors/actor_miner.go
@@ -228,7 +228,7 @@ func (sma StorageMinerActor) PreCommitSector(act *types.Actor, vmctx types.VMCon
 	}
 
 	if params.Epoch >= vmctx.BlockHeight() {
-		return nil, aerrors.New(1, "sector commitment must be based off past randomness")
+		return nil, aerrors.Newf(1, "sector commitment must be based off past randomness (%d >= %d)", params.Epoch, vmctx.BlockHeight())
 	}
 
 	if vmctx.BlockHeight()-params.Epoch > 1000 {
diff --git a/chain/types/tipset.go b/chain/types/tipset.go
index 0939fef1c..1836fe813 100644
--- a/chain/types/tipset.go
+++ b/chain/types/tipset.go
@@ -9,6 +9,7 @@ import (
 
 	"github.com/ipfs/go-cid"
 	logging "github.com/ipfs/go-log"
+	cbg "github.com/whyrusleeping/cbor-gen"
 )
 
 var log = logging.Logger("types")
@@ -52,6 +53,10 @@ func (ts *TipSet) UnmarshalJSON(b []byte) error {
 }
 
 func (ts *TipSet) MarshalCBOR(w io.Writer) error {
+	if ts == nil {
+		_, err := w.Write(cbg.CborNull)
+		return err
+	}
 	return (&ExpTipSet{
 		Cids:   ts.cids,
 		Blocks: ts.blks,
diff --git a/lib/statestore/store.go b/lib/statestore/store.go
index 52734bd2b..f578c17e3 100644
--- a/lib/statestore/store.go
+++ b/lib/statestore/store.go
@@ -74,8 +74,8 @@ func cborMutator(mutator interface{}) func([]byte) ([]byte, error) {
 
 		out := rmut.Call([]reflect.Value{state})
 
-		if err := out[0].Interface().(error); err != nil {
-			return nil, err
+		if err := out[0].Interface(); err != nil {
+			return nil, err.(error)
 		}
 
 		return cborrpc.Dump(state.Interface())
diff --git a/lotuspond/front/src/StorageNode.js b/lotuspond/front/src/StorageNode.js
index 741932db9..ef50c615d 100644
--- a/lotuspond/front/src/StorageNode.js
+++ b/lotuspond/front/src/StorageNode.js
@@ -9,12 +9,15 @@ const stateGettingToken = 'getting-token'
 
 let sealCodes = [
   "Unknown",
-  "Pending",
+  "AcceptingPieces",
+  "Committed",
+  "Committing",
+  "CommittingPaused",
   "Failed",
-  "Sealing",
-  "Sealed",
-  "Paused",
-  "ReadyForSealing",
+  "FullyPacked",
+  "PreCommitted",
+  "PreCommitting",
+  "PreCommittingPaused",
 ]
 
 class StorageNode extends React.Component {
diff --git a/storage/cbor_gen.go b/storage/cbor_gen.go
index 518db6692..38e70c020 100644
--- a/storage/cbor_gen.go
+++ b/storage/cbor_gen.go
@@ -90,7 +90,7 @@ func (t *SectorInfo) MarshalCBOR(w io.Writer) error {
 		return err
 	}
 
-	// t.t.State (api.SectorState)
+	// t.t.State (uint64)
 	if _, err := w.Write(cbg.CborEncodeMajorType(cbg.MajUnsignedInt, t.State)); err != nil {
 		return err
 	}
@@ -173,7 +173,7 @@ func (t *SectorInfo) UnmarshalCBOR(r io.Reader) error {
 		return fmt.Errorf("cbor input had wrong number of fields")
 	}
 
-	// t.t.State (api.SectorState)
+	// t.t.State (uint64)
 
 	maj, extra, err = cbg.CborReadHeader(br)
 	if err != nil {
diff --git a/storage/miner.go b/storage/miner.go
index 18449a42c..4cec6c94b 100644
--- a/storage/miner.go
+++ b/storage/miner.go
@@ -80,6 +80,11 @@ func NewMiner(api storageMinerApi, addr address.Address, h host.Host, ds datasto
 		secst: secst,
 
 		sectors: statestore.New(namespace.Wrap(ds, datastore.NewKey("/sectors"))),
+
+		sectorIncoming: make(chan *SectorInfo),
+		sectorUpdated:  make(chan sectorUpdate),
+		stop:           make(chan struct{}),
+		stopped:        make(chan struct{}),
 	}, nil
 }
 
diff --git a/storage/sealing.go b/storage/sealing.go
index cb377172a..d1883be3d 100644
--- a/storage/sealing.go
+++ b/storage/sealing.go
@@ -81,15 +81,18 @@ func (m *Miner) onSectorIncoming(sector *SectorInfo) {
 }
 
 func (m *Miner) onSectorUpdated(ctx context.Context, update sectorUpdate) {
-	log.Infof("Sector %s updated state to %s", update.id, api.SectorStateStr(update.newState))
+	log.Infof("Sector %d updated state to %s", update.id, api.SectorStateStr(update.newState))
 	var sector SectorInfo
 	err := m.sectors.Mutate(update.id, func(s *SectorInfo) error {
 		s.State = update.newState
+		if update.mut != nil {
+			update.mut(s)
+		}
 		sector = *s
 		return nil
 	})
 	if update.err != nil {
-		log.Errorf("deal %s failed: %s", update.id, update.err)
+		log.Errorf("sector %d failed: %s", update.id, update.err)
 		m.failSector(update.id, update.err)
 		return
 	}
@@ -111,10 +114,13 @@ func (m *Miner) onSectorUpdated(ctx context.Context, update sectorUpdate) {
 }
 
 func (m *Miner) failSector(id uint64, err error) {
+	log.Error(err)
 	panic(err) // todo: better error handling strategy
 }
 
 func (m *Miner) SealSector(ctx context.Context, sid uint64) error {
+	log.Infof("Begin sealing sector %d", sid)
+
 	si := &SectorInfo{
 		State:    api.UndefinedSectorState,
 		SectorID: sid,