Sonar with Yamaha keyboad

I have a Yamaha 2100 keyboard, and Sonar 4 on a Win XP PC, and Sonar 2 on a Win 98 PC. Midi files created on the keyboard can be edited using Sonar 2 and replayed on the keyboard without problems. However, if the same files are edited using Sonar 4, the revised file will not play on the keyboard. The keyboard score view shows the tune is progressing, but no sound occurs. What can I do?