I noticed that, in the results screen, after running Ad-Aware Personal or Ad-Aware Plus, Negligible Objects tab, the descriptions that used to appear in the Descriptions column are all gone. I've uninstalled and reinstalled (the latest versions), with no change. These descriptions used to be very helpful in determining which MRU lists should be deleted. Anybody else seeing the problem, or is it something unique to my system (XP Pro SP2)?

I don't think it's unique to you, although you could try uninstalling and then running a registry cleaner (such as RegSupremePro) removing all remnants of AdAware from the registry. Then re-install.

I just checked and i dont have any discriptions aswell , don't know if they where there before though. I never looked , You should be able to safely delete all MRU entry's anyway.