Exporting MIDI (again compatibility)

I entered a nice track with electrical guitars and piano and exported it as MIDI file.
When I opened the resulting MIDI in my recording software (Cakewalk Guitar Tracks) as MIDI background track and played it back, those three different instruments showed up as one, and I heared all three playing simultaneously.
I was also not able to select one of the individual instruments.
I wonder if something is wrong with the mapping different parts to different instruments.
When imported a file earlier, a diverse range of instruments all became piano parts.
Again I would be very thankful if someone could recommend some software with decent MIDI editing skills.
Right now it leaves me guessing which software is producing incorrect MIDI files.
Regards,
Marc
When I opened the resulting MIDI in my recording software (Cakewalk Guitar Tracks) as MIDI background track and played it back, those three different instruments showed up as one, and I heared all three playing simultaneously.
I was also not able to select one of the individual instruments.
I wonder if something is wrong with the mapping different parts to different instruments.
When imported a file earlier, a diverse range of instruments all became piano parts.
Again I would be very thankful if someone could recommend some software with decent MIDI editing skills.
Right now it leaves me guessing which software is producing incorrect MIDI files.
Regards,
Marc