Mongo crashes if query for collection in new db

A new db is used and a query is executed against it causing the mongod process to crash.

Step to repro:

1. Initiate mongo console to mongod
2. Type "use foo" where "foo" is a new database name (never used before)
3. Type "db.Bar.find()"
4. Watch process die horribly...

NOTE: I made sure to clear out all data files to be sure I wasn't using a previously existant db.