Seriously? "Crazy high" isn't exactly how I would describe a $600 price tag, especially if that applies to future models (i.e. 1 GHz "Pandora 2"). What would you use your Pandora for--emulation? If that's your main interest, it might not be the device for you (although it's pretty stellar for...
First post from a new Pandora owner here--love this little device!!
Mednafen is a little tricky; your problem is almost certainly the CD BIOS files. The directory for the syscard files for Mednafen is:
/pandora/appdata/mednafen/.mednafen/pce_bios/
Notice the hidden ".mednafen" directory...