Not all RAM "usable"

[Biosproblem]

Hello, I have a Gigabyte P67A-UD4-B3 motherboard and 4GB of PQI RAM, on a 64-bit Version of Windows 7.

When I go into system properties it says "4.0GB of ram, 1.32GB Usable". All the others in resource monitor is "hardware reserved"

I have updated to the newest BIOS and that only limited the amount of "usable" RAM.

I unplugged 2GB of the ram and all was usable.

Makes absolutely no sense.

My System:
Gigabyte P67A-UD4-B3
Intel i5 2400
4GB of PQI 1333 RAM
Gigabyte 5770 1GB VGA Card
1TB Sata HDD
500GB Sata HDD
LG Bluray disk drive (SATA)
350W power supply

 

[davcon]

System configuration utility
Boot tab
Advanced options
uncheck maximum memory

 

[Biosproblem]

Didn't work. It was checked (even though I unchecked it) and when it restarted it went back to 1.72GB usable.