blender lagging 2.66.1

i’ve got windows 8 64 bit with 16gig ram and a fx6100 cpu and a gtx660ti gpu but have been getting lagging in blender a lot recently I 've tried 2.66 rv 54698,54881,55051,55113 all with the same problems I thought it was my scene but on tring basic scenes I’m getting the same problems:( shame because it looks a great release.
I tried reinstalling my graphics drivers (314.07) but no joy…

Try installing a bit older graphics drivers.

In the meantime I tried beta driver 314.14 and it’s much better thanks for replying anyways.