Am upgrading from the 0.7.0 nightly build for 31/08 to the beta 2. 

I've deleted the Schema* CF's in the system Keyspace and when I start the new install I get this...

java.lang.NullPointerException
        at org.apache.cassandra.io.sstable.IndexSummary.complete(IndexSummary.java:60)
        at org.apache.cassandra.io.sstable.SSTableReader.load(SSTableReader.java:270)
        at org.apache.cassandra.io.sstable.SSTableReader.open(SSTableReader.java:173)
        at org.apache.cassandra.db.ColumnFamilyStore.<init>(ColumnFamilyStore.java:157)
        at org.apache.cassandra.db.ColumnFamilyStore.createColumnFamilyStore(ColumnFamilyStore.java:334)
        at org.apache.cassandra.db.ColumnFamilyStore.createColumnFamilyStore(ColumnFamilyStore.java:322)
        at org.apache.cassandra.db.Table.initCf(Table.java:301)
        at org.apache.cassandra.db.Table.<init>(Table.java:249)
        at org.apache.cassandra.db.Table.open(Table.java:102)
        at org.apache.cassandra.db.SystemTable.checkHealth(SystemTable.java:142)
        at org.apache.cassandra.service.AbstractCassandraDaemon.setup(AbstractCassandraDaemon.java:99)
        at org.apache.cassandra.thrift.CassandraDaemon.setup(CassandraDaemon.java:54)
        at org.apache.cassandra.service.AbstractCassandraDaemon.activate(AbstractCassandraDaemon.java:201)
        at org.apache.cassandra.thrift.CassandraDaemon.main(CassandraDaemon.java:133)


Any thoughts ?
Aaron