hmmm, well you have the same graphics card as me and my renders come out as crisp as christmas morning so i can be little more help to other than saying good luck!!!

ok, well it should look ok, have you spoken nicely to your graphics card lately? I have had this problem before and it was a corruption of the preferance settings and i closed down maya and deleted...

Also sometimes incorrect lighting can do that. What render setting do you it on?