thanks guys. Unfortunately, I don't have any extra video cards lying around, but I will clean the connector.
Right now, I have an Antec 350w power supply. I thought it would be enough for my system. Do you suggest I move to one up in the 400w range? There are a total of seven fans inside (2 80mm case fans, 2 80 mm ps, one on the cpu, one on the northbridge and one on the GeForce). Could this be pushing my power supply to its limits?