Display has green tinge with Nvidia Card

My LCD display has recently aquired a greenish tint. It started out as an intermittent problem where the on the intial boot up into windows the display would have a greenish tint and after a few minutes would correct to a normal color balance. Now the green is here to stay. I don't think it is the monitor (SOny SDM-v72w LCD), but suspect it may be an issue with the nvidia gforce fx5600 card. I can't find a means of diagnosing where the issue lies or a way of adjsuting the color balance on the card. I am using windows XP sp2 media edition on a SONY pcvrz30cg computer. I check the Nvidia site with no results, as well as SOny and Microsoft. Any suggestions before I replace the card?