Men Of War Vietnam crashes

[nrenock2]

I recently purchased Men of War Vietnam Special Edition from the Amazon download store. The game installed fine and seems to work fine except when I click on a vehicle I want in reinforcments. I get an error saying Vietnam.EXE has caused an error and needs to close. The error details says it is a BEX error which is some kind stack overflow / DEP problem. It doesnt matter which vehicle I select it gives an error. I also installed this on my sons computer which is running Windows XP SP3 and the same exact thing happens. My computer is runnning Windows 7 Pro 64-bit. I tried installing direct x again and turning off data execution protection (DEP) for vietnam.exe and still get the same issue....any answers would be appreciated.
Thanks