Fn Keys not working right

Ok so on friday i got my old rundown tosiba laptop replaced with a new dell laptop at PC world. Everything was running fine until while i was playing Dawn of war 2 game i press f1 ingame to do something.....in game...but it brought up what Fn + f1 should have, if i press Fn + F7 it should mute my sound but it does nothing yet if i press f7 on its own it mutes my sound. I know its nothing i've done because about an hour before me typing this i wiped the hard drive and the problem is still there,I never had this problem with my last laptop. I have tried pressed num lock on and off, Fn + num lock Fn + shift, FN +f11 every combo i can find many different forums and its STILL stuck on. Im a bit annoyed mainly because the ppl at PC world  said they never seen the amount of the problems my last laptop had and now i get brand new one.....this. Anyways any help anyone could give would be great, i've also sent an email to dell support see what help they can give.

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System Information
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Time of this report: 5/2/2010, 16:15:33
       Machine name: SCOTT-PC
   Operating System: Windows 7 Home Premium 64-bit (6.1, Build 7600) (7600.win7_rtm.090713-1255)
           Language: English (Regional Setting: English)
System Manufacturer: Dell Inc.
       System Model: Studio 1745
               BIOS: Ver 1.00 A01
          Processor: Intel(R) Core(TM)2 Duo CPU     P7550  @ 2.26GHz (2 CPUs), ~2.3GHz
             Memory: 4096MB RAM
Available OS Memory: 4090MB RAM
          Page File: 1726MB used, 6453MB available
        Windows Dir: C:\Windows
    DirectX Version: DirectX 11
DX Setup Parameters: Not found
   User DPI Setting: Using System DPI
 System DPI Setting: 96 DPI (100 percent)
    DWM DPI Scaling: Disabled
     DxDiag Version: 6.01.7600.16385 32bit Unicode