Windows 7 - Starcraft 2 Beta Performance

Hi

I wonder what had happened...

I use Windows 7 on a MacBook Pro 13" (running on BootCamp)
2.53Ghz P8700
4.00GB (2.72GB usable) RAM
256MB NVidia 9400GM

Before this, I used the Medium settings for graphics (except for the unit portrait, I use 3D) and everything run smoothly

Recently, it run smoothly at early game. After about 2-3 minutes playing, performance drop drastically. Very slow... Same thing occurs when I'm using the low settings...

I don't understand what had happened....

Heya! Great to see another SC 2 Junkie out there! I haven't received a beta-key, *yet* so im just playing on a cracked version of the game with a AI. But my settings are all on ultra.
But you can try putting the unit portrait to 2d - for me i don't really care.
But it could also be due to the ram amount which is usable...
Though - my ultra settings are on my new and home made computer!!(I'll be putting up pics soon )
My New Home-Made Computer:
HDD: Western Digital Caviar Blue 320GB 16MB 7200RPM SATA2
Graphics: Dual ATI Radeon HD4870 X2 2GB in Quad-CrossFireX
RAM: 12GB Triple-channel Corsair Dominator: 6 x 2048MB DDR3 1600MHz
Cooling: Water Cooling(self contained) - AWSOME!!!) + Fans
Processor: Intel Core i7 2.66GHz x 4 with HyperThreading 4.8GT/s FSB 8MB cache
Mobo: EVGA X58 ATX LGA1366 DDR3 3PCIE-16 PCI-E1 2PCI SLI SATA2 eSATA Dual GBLAN

Computer Name: (The DDominator!) Rawr!!!

I also use the cracked version...

Nice PC you have, AWESOME!!!
How many buck have you spent on that?