Terry, the only thing that comes to mind is that you need to be up-to-date with FSUIPC in GW3,
"... ensure you have the latest FSUIPC installed (3.74, as of April 2,
2007,) available here:
Version 3.7 is the earliest version which the starter gauge will work with."
The current FS9 latest is 3.999 I believe but anything after 3.74 should work.