hi guys...
now, the rollback segment have 3 states: online, offline, needs recovery.
Ok, so the 3'd state meens that the rollback segment 'X' had a transaction active in it (active= non commited). Now
you have 3 possibilities:
1. try to release the transaction active (it remains in the datadictionary), by relesing in the DBA_2PC_PENDING view or
PENDING_TRANS$ table.
2. if nr.1 don't work you will have in the data dictionary for ever the segment 'X' with the nees recovery status until you recreate the database.
3. (at your own risc):
IF nr.1 DON'T WORK.
update manualy undo$ table change the values status$ to online (numeric). Run catalog.sql & catproc.sql , then try keep offline by command and finaly drop.