Your card uses the same chip as the 3700, which passed Vista testing in AC12 (
http://www.archicadwiki.com/Video%20Cards%20for%20ArchiCAD%2012).
Are you using the recommended driver version? If not, get it from here:
32-Bit:
http://www.nvidia.com/object/winvista_x86_162.65.html
64-Bit:
http://www.nvidia.com/object/winvista_x64_162.65.html
Josh Osborne - Central Innovation
Mac Mini