Barry,
Moving to 9i wasn't difficult? Isn't it that all the references to "new" when creating packages and so on, need to be changed? Or it's almost an out-of-the-box migration ... ? I am curious ... :)
I also have a OACS 5.1 running on 10g on a clone of RHEL 3.0 ... I noticed that the web interfaces for the DB administration is taking almost 800MB of RAM !!! I can shut it down and then my server, which only has 1GB RAM becomes quite usable again ... I am not sure if that is actually something I should not do, because it might be stopping all the new features of 10g (like self diagnosis and almost self tuning thingies)
Cheers
/B