In the folder list, press menu, select show hidden, then go to that folder
or picture(s) press menu and then properties. Take the check out of
the hidden box at the bottom and you're done.
Do what AG said and you should be good. But in case you don't know how to get to the folder list, open the media app, press the bb key and select explore.
Posted from my CrackBerry at wapforums.crackberry.com