Mutexes table takes 100% CPU in Oracle


We are experiencing a very estrange behavior in a Production Environment running on Oracle11g.  Sessions created by eB are executing multiple select statements against de MUTEXES table and hangs the hole database instance.  MUTEX table is empty.  We have double-checked that no transactions are pending.  The DB instance was shutdown twice as the eB Services and Package were shutdown multiple times.

Any idea where to look to find out what is happening?

Thanks in advance, kind regards,