I am not sure what causes this display problem, but I have experienced similar problems before. Files that worked 100% percent in FSX had to be edited after FSX was re-installed.

I would load the panel in FSPS to see if all gauges are called up.

Try to remove your panel completely (back it up) and copy another aircraft's panel in there. Start FSX and load the aircraft shut down. Re-installed your panel and try.

Also try to copy all your gauges to the general gauges folder of FSX.