Do the pictures look familiar? Something from a vidcast or someplace you went in a browser? If so, the app (vidcast or browser) wasn't written correctly. Find the folder it stores the photos in (it's probably a bunch of subfolders named 736131213149529, etc.) and create a file named .nomedia (no charactrs to the left of the dot, and the file doesn't have to have content - only the file name matters) in the main folder. That will keep Media Scanner from scanning the main folder and finding the subfolders and the pictures in them. If Media Scanner doesn't find a picture, a picture app won't show the picture (or the folder (album) it's in.
(Any app that stores media files that you didn't specifically tell it to store should create that file in its top-level folder.)