Kingdom Hearts: Birth by Sleep - US - ULUS10505

[vmenge]

Hey guys, I need some help getting this to run properly.
For some reason I'm getting incredibly low FPS (from 6 to 10 tops). I'm using the SVN build 2736. The only video settings I'm using are:

• Only GE Graphics
  
• Enable Saving GE screen to Textures instead of Memory
  

I'm also using Media Engine and decoding files with SonicStage.

My pc specs:
OS: Windows 7 Ultimate 64-bits
Processor: AMD Phenom II X4 955 3.2Ghz
Memory: 8GB DDR3 1333
Video Card: Radeon HD 5970 2GB

Is this normal, or am I doing something wrong?
Thanks!