Okay, now I'm pretty sure that it is a Bug and not a problem of the code. Then as the problem occured again I tryed it on a simple Script:

function main()
{
level_load("level.wmb");
wait(3);

}

This is ALL the script, it isn't really much that could make such a lag is it?

And still the Debuger makes 1 FPS and my same PC lags. Like I sayed before the normal compiling works fine!
I made a video so you can see better what exactly is the problem:
http://de.youtube.com/watch?v=Pn4umgkm2FE

As you see. After closing the window my mouse and all runs fluid again. And I don't think it is a Problem with my hardware.

I at least I hope it

Thanks.