I struggled so much trying to get my WMC to keep updating (since my tuner wasn't compatible with digital OTA signal according to MS). It would work once I set it up but then it would download 2 weeks worth of EPG and never do it again. In two weeks I would have to blow the WMC out and set everything up again. Finally it worked when I modified host file (and who knows what else I did to get it to work).
I also had problem with WMC reverting back my strip setup. I had to disable folder's (where this data is held) write permissions to everybody including Admin. Now I can't really open it, but my customized menu strip looks the way I want it.