I had the same problem last week. I fixed it by restoring a backup I had made just a day before or so. Not exactly sure what caused it, but I have an idea it was caused by an older version of MemMaid I was still using. It probably did more damage to my registry that it did good. I've had no time to test that out though...
Maybe it'll help.
I own a T-Mobile MDA Pro since May 2006. I'm just starting to learn about upgrading. After having learned enough I will be able to give you something in return, I hope...
T-Mobile MDA Pro, Unlocked & SuperCID
ROM by Thingonaspring
ROM version: 2.11.10 PDS
ROM date: 08/02/07