Not sure if anyone else suggested this or not but could the directory be set to read only and that might be the reason the settings are not saving? Also if they are not the logged in as administrator, this can also cause a problem. I had this issue until I deleted the .Net user on my XP machine, after getting rid of that user everything seemed to save perfectly fine. The only issue I'm having now is that my group windows aren't functioning correctly. I read earlier up that there was a fix in the works for this going in.
Will this also address the auto assist in the group window? Sorry if this has been addressed already, its early and I haven't finished my 1st cup of coffee yet!