often its not the card its the driver when I first got my G-3 I got a gforce 6600 and it still wouldn't work went to the web site and down loaded the driver from there.
the other night I down loaded the G-3.5 and some new planes and what do ya know freeze up so back to the web site for the latest driver and poof the sim is good to go.
BTW if you havn't seen or used the 3.5 it is pretty nice definitely a up grade the planes fly better and I think they are closer to real life