ALTGPS gauge prompting error message

I just downloaded the Dassault Mirage IIIC "Vexin" from http://www.attach2.com/mirage/home.html , but when I select it in FS 2002 I am getting an error message stating that ALTGPS2.gau were incompatible and would be deactivated. However, contrary to the message saying I could still run the plane without that gauge I am getting the send/don't send box and subsequent FS relaunch.Anyone know of a way to get this gauge working? AFAIK it is supposed to be some kind of moving-map display - just like the default FS 2002 GPS gauge, but with a map underlaid.Thanks!