[johnnymac]

I popped my Garmin XT SD card out of my Touch and straight into my Touch Pro and it worked fine... Did you try this:

Start up garmin, and click agree and then click on the little icon at the top left corner of the screen...(the place where the signal strength should be.)

Click disable and then go and select Use Serial GPS COM4:COM4

That should work.... if not try using GPS intermediate driver.

If that still doesn't work, your SD card could have gotten corrupted. Call tech support at Garmin.