Nodes Don't Restart: Assertion Error on Serializing Cache provider

I stopped Cassandra on one of our 1.1.2 nodes and I couldn't start it any more. System.log didn't have much useful info but output.log had this:

java.lang.AssertionError
at org.apache.cassandra.cache.SerializingCacheProvider$RowCacheSerializer.serialize(SerializingCacheProvider.java:43)
at org.apache.cassandra.cache.SerializingCacheProvider$RowCacheSerializer.serialize(SerializingCacheProvider.java:39)
at org.apache.cassandra.cache.SerializingCache.serialize(SerializingCache.java:116)
at org.apache.cassandra.cache.SerializingCache.put(SerializingCache.java:174)
at org.apache.cassandra.cache.InstrumentingCache.put(InstrumentingCache.java:45)
at org.apache.cassandra.db.ColumnFamilyStore.initRowCache(ColumnFamilyStore.java:430)
at org.apache.cassandra.db.Table.open(Table.java:124)
at org.apache.cassandra.db.Table.open(Table.java:97)
at org.apache.cassandra.service.AbstractCassandraDaemon.setup(AbstractCassandraDaemon.java:204)
at org.apache.cassandra.service.AbstractCassandraDaemon.init(AbstractCassandraDaemon.java:254)
at com.netflix.priam.cassandra.NFThinCassandraDaemon.init(NFThinCassandraDaemon.java:41)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.commons.daemon.support.DaemonLoader.load(DaemonLoader.java:212)
Cannot load daemon
Service exit with a return value of 3

Deleting the stuff in saved_caches folder fixed the problem.