thinking on a BIOS upgrade

Hello,
I got a computer in which I decided to change RAM memory cards.
These (2) RAMs are:
Brand: Crucial Technology DDR Ram 266 Mhz
and when I ran memtest86 tool, both of them have errors.
So I decided to change them and purchase a new ones.
I bought:
Brand: Patriot DDR RAM 512 Mb 266 Mhz
but when I try to power on the computer, the motherboard beeps
the beep length is equal but the pause between them is the difference
1-3-2 (1 beep , large pause, 3 beeps , large pause ,2 beeps, silence)
I googled and it says it could be the motherboard, but if it would be the motherboard I wouldnt be able to power on the computer again using any other Ram memory am I right??, but somehow I can power on the computer using the old Memory Cards .
Im thinking on upgrading its BIOS to A12 so PC can read the new Memory Cards , currently it has BIOS version A10 what u guys think??

Server Details
Dell Power Edge 1600 SC OS : RHEL4 , Intel Xeon Processor 2800 MHz. Bus Speed: 512 Mb.

Is the memory you tried ECC? Your server requires it, I believe. Another thing is, I would test your RAM with memtest86+ and not memtest86.

Your Patriot memory is more than likely not ECC and causing your issues.

OK yes you're right I guess the server only supports ECC Ram memory.
Thank you very much for answering....
I am going now to get the right RAM card and I'll let you know how it went.