Sandybridge + Nvidia Geforce GT550m

Hey guys i have a problem with my teeworlds..
People with sandybridge cpu might know that you can choose to run a program with either the dedicated graphics card or the cpu built in graphics chip.
The problem is that my computer automatically chooses the sandybridge gpu instead of the nvidia.
This can be changed by me ofcourse but it seems that teeworlds runs even worse on the nvidia card :S

Problems with sandybridge:
-Delay on mouse cursor with and without vsync turned on
Problems with nvidia:
-Delay on mouse cursor with vsync on, not without
-Screen flashes every 2-3 minutes running full screen

All my drivers are ofcourse up to date.
The computer is completely new and can run crysis 1 and 2 without any problems wich makes this even more weird..
I noticed that when running minecraft in fullscreen the screen flashes every 2 and 3 minutes aswell.. the nvidia card is chosen automatically when running minecraft.. My guess is that the problems has something to do with OpenGL since both games is running on that..

The computer: http://www.merlin.dk/product.aspx?prodid=428057

really hope that someone can help me out here!

Nicolaj,