I'm going to guess that your card has a temperature sensor on it an is speeding up the fan because it is getting hot. Maybe the new drivers are allowing this. If this is the case, you have a couple options: a) Cool your case better, which may make the GPU not get as hot and not need the extra rpm'age. b) Get a quieter fan for your card. They are easy to replace.
While, A is probably the easiest, B is more likely to actually work.