Can't launch it - at all!

[Manjerico]

After trying to launch Super Meat Boy, I'm shown the following error:
"Pixel Shader Error: c:\program files\steam\steamapps\common\super meat boy\memory(4,154): error X1005: string continues past end of line error X3501: '_fragMain': entrypoint not found

Vertex Shader: vs_3_0
Pixel Shader: ps_3_0

-----------Driver Details-----------
Driver: aticfx32.dll
Description: ATI Radeon HD 4800 Series
Device Name: \\.\DISPLAY1
Product: 8
Version: 17
SubVersion: 10
Build: 1124"

I'm running Windows 7 32 bits. Does anyone know how to get rid of this?!