Alienware M11xR2 performance

Hi,

I have had my Alienware M11xR2 for a couple of months now.  I used to play Starcraft 2 on it (I could only ever play on Medium settings) but now the performance has degraded so much that I can't even play a single game on the absolute lowest settings.  I get a message which says "Your computer is slowing down the game. Please turn off applications..." etc.  This seems pretty ridiculous considering others are playing on high or ultra with the same setup.

I have reinstalled the NVidia drivers, checked to make sure nothing intensive is running in the background, made sure it is whitelisted for GeForce video card...  i have checked countless boards about suggestions and tips but nothing seems to make much sense or work.  Are there some new drivers out there I should use?

Please advise if there are any known fixes or hardware problems that others have been experiencing...or maybe some benchmark I can run that can help me figure out what is wrong with it.  Here are some additional specs for my system:

Windows 7 Home Premium
Intel Core i5-520M Processor (2.4GHz, 4 Threads,3M cache, turbo Boost up to 2.93GHz)
4 GB DDR3 SDRAM 1333MHz
1 GB  NVIDIA GeForce GT 335 M 

Thank you very much,

-Kenny