Help with NesterJ and DGen please!

I have the NesterJ and the DGen emulator on my PSP. I've been a 2.0 user for so long and I finally got the chance to downgrade and now I'm stuck on this!

Anyhow, I have the emulators and I place the roms into the specified folder, but they won't show up when the actual emulator loads up and when I browse back to the PSP via USB connection, they're always gones.

Is there a certain extension they need to be? If so, can someone fill me in on the extensions required for NesterJ and DGen or maybe specific instructions on how to run them. Thanks, this has been a real pain.

I got the roms to load, didn't do anything different they just started showing up.

Is there a Street Fighter ROM compatible with the DGen emulator? I own almost <i>every</i> Street Fighter game in existance, I'm a fiend for 'em!

I got NesterJ running but I'm still trying to get DGen running.