Windows XP is not recognizing RAM properly

[crashdet]

I have a Toshiba A65-S126 Satellite Laptop which is running Windows XP sp3. I recently upgraded the RAM from a 256 mb to a 1gb plus the 256 mb built into the motherboard should gave me 1.25 gb. When I start it, the BIOS indicates 1.24 gb of RAM but Windows only recognize 512 mb. The boot.ini shows no maxmem settings (see below). Anybody have any suggestions??

[boot loader]
timeout=30
default=multi(0)disk(0)rdisk(0)partition(1)\WINDOWS
[operating systems]
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Home Edition" /forceresetreg /fastdetect /NoExecute=OptIn

 

[crashdet]

UPDATED - When I first start the computer after it has been off for a while, the Computer Properties shows the RAM as 1.18 GB, but shortly (few Seconds) after Windows finishes loading I get the blue screen of death (PAGE_FAULT_IN_NONPAGED_AREA) and when Windows restarts, it just shows 512 MB but the computer runs fine (just slow), Could this be bad memory?

 

[adamh9]

so you have ONE stick of 1GB memory and one stick of 256MB?

 

[crashdet]

so you have ONE stick of 1GB memory and one stick of 256MB?

No, just one stick of 1 gb and it has 256 mb RAM built into the motherboard.