GPS Won't Function

I downloaded the freeware Apollo MX-20 and Garmin 430 / 530 GPS's from Keith Giveans and replaced the GPS that ships with FS9. They have worked for a long time now, but have stopped working. The panel will load and in the case of the Garmins, if they are not turned on everything works. Turn them on, and the sim hangs and has to be restarted. I have the RealityXP Garmin 530 and it works fine, but as you know you can't import FS flightplans. The last thing that I installed before they stopped working was Squawkbox. I have replaced the files, re-edited the panel.cfg files and re-installed them again, but neither they of the default GPS work. Any ideas?