Erm, sorry, I just chimed in - I'm not the original poster, just a guy with the exact same error message. My wcl file resides on a local harddisk; and when it stops working, I find it completely emptied: zero length file, zero bytes data in it (by hex editor). I've been trying to reproduce the problem but that's not the way it works apparently, even though it DID happen more than once before. I'm on WinXP media center edition, using the lite version wallpaper cycler, btw. And I did save a copy of the currently-working wcl, just in case it gets hosed again.