I have a P5B Deluxe/Wifi with an Core Duo 2 6700 and 2x1GB A-Data PC6400 memory modules intsalled in the two yellow slots.

Today i bought a pair of Mushkin PC6400 512MB modules, same cas and voltage.

When i install them, my PC boots fine but the bios dosent recognize more than 2GB.

When the PC is booted to the desktop and i run CPUz it tells me that there are 3GB installed but XP dosent recognize more than 2GB.

The PC is not overclocked or tweaked in any way and the 2 Muchkin modules works fine when installed seperately or togheter.

I have tried to mess around in the bios to solve things but to no avail.

Why cant i get the board to recognize all 3 GB of memory?