Pocket Piano Midi and PC or iPad

do anybody knows? I have a PP Midi, and bought one of those Generic Usb-Midi 2.0 cable. when i connect a Yamaha Keyboard works fine, it goes fine with iPad (using camera connection kit) and Pc. But when i try to connect the PP to pc or ipad, nothing happens. . the midi ports are working well, I know it because there’s no problem between my yamaha and pp midi connection.

Btw, PP works with iPad, at least I know it because I got the answer from the C&G e-mail support