DLC problem please help

So I recently downloaded Second Assault on PS3 and ran into a few issues. When the file says downloaded and installed, I go to the server browser, type in all my settings, and when it finds open servers, it gives me the option to buy the DLC instead of joining the match. It tells me to buy the DLC when I  have already downloaded the file. I've tried deleting the file and re-downloading but nothing works has sombody an idea on how to fix this