The only thing I can suspect is, not too long ago I accidentally partitioned my SD-ext to 0mb in CWM.
I am using the lastest Kang CM7.2 Photon Dev Team. Install location: Internal, and "use internal storage" checked.
I can't determine the cause, but certain directories & files that I put on sd-ext are disappearing on me, some within hours (wallpaper folder). The other strange thing happening is a lot of my image files (.png icons) become unreadable & appearing to be corrupted. These same files can be stored on internal SD without this happening. I have checked the disk in windows w/o errors.