Ram - tested, but not compatible?

[Tauron]

Ok, I am trying to install a stick of 512mb DDR333 alongside a 256mb DDR333 stick. The 512 is double sided, the 256 is not. I am installing in an AsRock K7VM4 Mobo, with an XP 2500+ and WinXP Pro.
This ram is new and has been tested in a friends computer, where it worked perfectly.
When I install it in my computer, it detects it, goes through the P-O-S-T fine, loads WinXP....gets the the 'welcome' screen, and then gives me a BSOD (Blue Screen of Death) and tells me to reset my computer.
Now I cant return this ram, as it isnt faulty, and I see no point in running memory test programs, as this ram has been tested working.
I have looked through the mobo's website, but it offers no help.
If anyone could give me a little advice, I would be v. grateful.
Thanks.

 

[etp777]

How has it been "tested working" if you see no point in running memory test programs?

 

[jammydodger]

Who companies manufacture the RAM? Try putting the 256Mb stick into a different slot as it might be trying to use it in dual channel mode and this could lead to instability with differnt types of RAM.

P4c 2.6@3.25
512Mb PC4000
2x120Gb 7200.7 in RAID0
Waterchill KT12-L30
Abit AI7
Radeon 9800Pro

 

[Tauron]

It has been tested in a friends computer, and worked.
The brand of ram is Ramos, and the ram doesnt work in any configuration, with the other stick, without, in whichever slots. Thanks.