Unable to shutdown Vista after running CF

OK. So here's the problem I got every time I open Crossfire. Just - EVERYTIME.

After opening Crossfire - it doesn't matter if it still runs or if I exit it - I can't shutdown my computer - the shutdown.exe doesn't work. I have a laptop with Windows Vista Basic and the game works fine. No crashes etc. But after the Luncher launches X-Trap, HGW.exe, Crossfire.exe - I can't shut it down -only by holding power switch - which isn't a good thing to do eveytime.

I can only hibernate it and that's all. I totally can't shut it down or make a fresh start (restar) of the system.

What is the poblem?

My laptop:

Dell Studio 1535
RAM: 3 GB
CPU: Intel Core Duo @ 2 Ghz
OS: Windows Vista 32-bit (Dell's OEM)

Do you have any solution to this problem?