just a note to say if you have Windows XP Media Center Edition 2005 (probably all versions actually) steer clear of registry clean programs such as Reg Mechanic they go through your registry and delete unnecessary keys..... sounds good but it didn’t count on Media Center I ran it a few days back and when I came to use Media Center it loaded then produced a crash report and died, took me ages to figure it out until I came to run Reg Mechanic again and realized This program deletes DLL files too so..... I restored the first backup and rebooted and media center worked fine so if you have that error on startup that’s your problem right there. Just restore the backup from Reg Mechanic. So you have been warned. Hey I know of a really cool media center show that may want to feature this check out www.iandixon.co.uk for more details.

<edit> ok ok so maybe it wasnt a DLL but according  to Crand its "one stupid registry entry. HKCU\Software\Microsoft\Windows\CurrentVersion\Media Center\MRU\PicturesMRU"  but the point remains it was reg mechanic bein crappy... (yes thats a technical term) the cause may not be the same as previously stated but the solution is the same.... thanks Crand... oh and Crand thanks for the second comment have u checked out the media center show podcast? have a look at the blog URL i nthis post this guy knows wat hes talkin about (ok he is my stepdad so im a bit biased) but the podcast is good