The Oracle monitor is a separate installation (I think) so I believe you'll get that error until you've installed it. If I was you I'd put a code snippit with both the above lines of code right next to each other and run it. That'll at least tell you if the Savepoint function is working correctly. Once you've confirmed that, I'd look at the datasets (if you're using them), and make sure you don't have CommitOnPost on. If you can get Oracle Monitor going, that'll make all of the above trivial, as you can simply look at the SQL being fired and see if a commit is occurring.
Hope that helps...sorry about the vague post last time.