Well, I've got both good and bad news..

Good: I published the level, and tried it on my mother's computer; it worked!
Bad: Then it must be MY computer there's something wrong with

I'm using a GeForce Ti 4200, and the newest driver from NVidia

But... Almost the same shader works fine in RenderMonkey...
But since I reinstalled my computer two weeks ago, I haven't used RenderMonkey...
I'll try this shader in RenderMonkey, and if it won't work there too...............

I'll post here again, if I can't get it working

EDIT:
RENDERMONKEY I LOVE YOU!!!
My hardware only supports vs1.1 and ps1.3 :S