I am getting the same bug whenever I attempt to complete the Advanced Restoration quest in Kvatch with Oleta.
Whenever you ask Oleta for training in the NPC dialogue window by clicking "Training", suddenly the number of "Kvatch" topics in Oleta's dialogue window start to multiply.
If you click on one of these "Kvatch" topics, then the others suddenly disappear.
This bug is happening after the Castle of Kvatch has been liberated, not sure that makes a difference or not.
I know that weird glitches in Oblivion such as this can cause crashes later on in the game, it happens to me a lot that when some weird bug happens it can eventually corrupt an entire saved game file.
Anyone know a workaround for this?