4gig ram in XP pro x64 showing as 2.93gb?

[m0rte]

Just installed another 2x 1GB sticks of Geil PC6400 bringing my total RAM to 4GB.
I'm running Windows XP Pro x64 but windows and the BIOS is only showing the total RAM as 2.93GB. CPUz, however, it showing the full 4096MB so it is all being picked up.
Win x64 should show all 4gb right? or am I missing something?

 

[m0rte]

Sorted!
had the change some northbridge memory mapping option in the BIOS