did you try to register it manually and see what happens. There is
command like alter system/database register.
Michael McMullen wrote:
> Solaris 8
> We got a ORA-00600
: internal error code, arguments:  at 10:15
> a.m as a table was being loaded by insert into select * from; I
> believe the undo tablespace filled up first.
> Two minutes after that the database was no longer registered with
> listener. It wouldn't register until rollback was completed. I'm
> logging a tar but anyone ever seen anything like this?