I have a gallery (MillValley2009) in X2 (just downloaded and installed) with five jpg images, all uploaded at the same time. For one of those images (file img_2503_+1_0_-2_std.jpg), if I try to edit or delete it, I get sent back to the gallery page. The other four images work fine. I checked the permissions of that image file and it has all permissions (777).
Any ideas?