diff --git a/reactive-banana.cabal b/reactive-banana.cabal
--- a/reactive-banana.cabal
+++ b/reactive-banana.cabal
@@ -1,5 +1,5 @@
 Name:                reactive-banana
-Version:             0.7.1.1
+Version:             0.7.1.2
 Synopsis:            Practical library for functional reactive programming (FRP).
 Description:         
     Reactive-banana is a practical library for Functional Reactive Programming (FRP).
diff --git a/src/Reactive/Banana/Combinators.hs b/src/Reactive/Banana/Combinators.hs
--- a/src/Reactive/Banana/Combinators.hs
+++ b/src/Reactive/Banana/Combinators.hs
@@ -142,7 +142,10 @@
 --
 -- > spill . collect = id
 spill :: Event t [a] -> Event t a
-spill e = E $ Prim.mapE concat (unE e)
+spill e = E $ Prim.filterJust $ Prim.mapE (nonempty . concat) (unE e)
+    where
+    nonempty [] = Nothing
+    nonempty xs = Just xs
 
 -- | Construct a time-varying function from an initial value and 
 -- a stream of new values. Think of it as
diff --git a/src/Reactive/Banana/Internal/PulseLatch0.hs b/src/Reactive/Banana/Internal/PulseLatch0.hs
--- a/src/Reactive/Banana/Internal/PulseLatch0.hs
+++ b/src/Reactive/Banana/Internal/PulseLatch0.hs
@@ -437,8 +437,8 @@
     _     == _      =  False
 
 instance Hashable SomeNode where
-    hashWithSalt s (P p) = hashWithSalt s $ uidP p
-    hashWithSalt s (L l) = hashWithSalt s $ uidL l
+    hashWithSalt s (P p) = hashWithSalt s . hashUnique $ uidP p
+    hashWithSalt s (L l) = hashWithSalt s . hashUnique $ uidL l
 
 {-----------------------------------------------------------------------------
     Combinators - basic