Well, databases take a lot of overhead to secure data against crashes, so what I said is much less outrageous than it may have seemed.
Anyway - run this command: less `which dbshut`
And then append immediate to every shutdown command and test the script by shutting down Oracle with a running AOLServer/SQLPlus session. If it works, everything will be fine and dandy, this is the script called by the Oracle rc script.
(You need to fiddle a bit with the spfiles when using Oracle 9)