Installing the Zalman VF900 too tight or not?

hey guys I bought this cooler and installed it, however im concerned it maybe too tight or not tight enough. The instructions say to tighten the screws but not when to stop. The screws are fairly taunt, however there is still considerable room between the stopping point on the mounts, you know where the little rubber washers would meet the board on the processor side. How do you know when the thing is tight enough? Also when do you know when its too tight? The board isn't bending or anything i don't hear any cracking. The main concern is that all the pressure is directly on the small gpu. It's only like the size of a dime so its a little bit scary.

I love it otherwise!

Thanks

When you say tighten as much as youc an are you talking about torqing on them? As in, till your fingers start to hurt from trying to keep a grip, or just until they are starting to get difficult to turn?

Thanks