I'm having the same problem described here and posted it a few days ago.
I'm quite sure it is a permissions problem, as I can't upload files or create albums until i manually recreated the image-gallery subfolders structure (/pagename, /pagename/_resampled, /pagename/Default-Album and /pagename/Default-Album/_resampled) with my own shell account.
Are you using a earlier version that doesn't have these problems, as I might think about downgrading the system so creating albums and uploading images works?