Ghost transaction in rollback segment

Hi all,

I have this funny problem: in v$rollstat I see there is one transaction using a rollback segment, already for days. However, there is no open transaction in v$transaction, there is nobody else logged in, and no sql actual executing. I already tried to take it offline, but it stays at 'pending offline'. I even bounced the database, but the (public!) rollback segment is then online again, with the ghost transaction. The other rollback segments in the same tablespace are OK, have a lot of writes, but this one had no writes at all, so it was never used.
However, I could start a new transaction (set transaction use...) in it. I cannot shrink it, and this is what bothers me, it just takes a lot of space away for the other rollback segments in the same tablespace.

How can I get rid of this ghost transaction? Or can I somehow drop the rollback segment?

GdB
Oracle 8.1.7.4 on Windows 2000 Received on Thu Oct 30 2003 - 01:31:29 CST