I do not use Mame32 so I can't be of much help, but since no one responded yet I could try something. Most emulators have a setting for where the ROM's live, make sure that is pointing to the folder where you put them. Also, some front-ends need to "compile" the Roms list - basically take an inventory of what Roms you have before you can actually play them, look for something like that. Other than that, you might be best going to the Mame32 website, see if they have a FAQ list or message board where people may have had the same issue as you.