Recording songs with a Casio MIDI keyboard

[gillang]

I have a Casio WK-1250. I also have a You Rock guitar. I do plug the guitar in the keyboard MIDI port so it gives me the chance to play alongside 100 tunes while using 200 different sounds instead of the 25 tunes and 75 sounds of the guitar. I have often recorded my playing to the internal keyboard memory but it's been impossible to do so for the guitar being plugged in the MIDI port. The keyboard won't record anything. I did contact Casio and since that model is more than a decade old, he doesn't have a clue if this is normal or not. Have you ever been able to record onto your keyboard internal memory while the song played was coming from an outside MIDI device? Thanks!