I have a problem, perhaps not knowing enough to solve it, but it appears that when I downloaded Paul Golding's MD80 panel to use with the new FFX DC9-51, his FS2k gps.gau file version replaced my FS2k2 version of the same file, now I am getting the 3rd-party error with this file each time I get into an aircraft. Any solution would be much appreciated.GrantM

Try to look up the gauge file in the cabs on the CD's and reinstall it. That's the best I can come up with for now. Good luck!