Well...you've done everything I would've tried.
At this point, if it's a usb receiver, I'd download this driver here:http://delorme.com/support/gps/uemat...=&P=17111&C=19
I know u shouldn't need it, as that's what's on the cd, but it's worth a try.
Also check this, if you haven't already:http://www.delorme.com/support/earth...rdpartytrb.asp
I know it's about 3rd party, but it's the same driver, I believe.
Keep us posted.