I have the same issue.
I had my HTC X7510 PDA working perfectly as an external GPS (using either Google Maps or Topo Memory Map) with Win XP and using Pete's GPSOut recommendations from the FSUIPC Manual (I did however have to use Com Port 8, not 9). Now with Win 7 Ultimate, 64Bit, using exactly the same settings in FSUIPC, and the very same PDA, I get no apparent GPS data on any COM Port! My PDA appears to log onto the PC the same way as it did with Win XP, but the one difference this time is that with XP, the software was Activesync and now Win7 it's called Sync Center and with that, there isn't the same options to turn off the "sync" portion and simple connect the PDA via a USB connection - perhaps therein lies the problem? I am using FSUIPC Ver 4.60a. Any ideas anyone? Greg