OCed P2B memory recognition problem on cold bootup

Hi, I'm asking this question for my brother. He has a P2B rev. 1.04 with a Celeron 900 @ 1200 on an Asus S370-DL rev. 1.02 slocket. Voltage is set at 1.9 and the BIOS version is 1012. He's using 3 sticks of 256MB Micron PC133 CL2 memory and OS is 98SE.

At 133 fsb and a cold boot, the mobo will only recognize 256MB of memory. However, from a restart, it jumps up to 512MB but not the 768MB that are actually there. If he runs 512MB, it still only recognizes 256 on a cold boot but does recognize the 512 after a restart.

Any ideas? Thanx.

Win9x can handle only 512 Mb of RAM, maximum. There's nothing to be gained by adding an extra 256 Mb. In fact, the surplus memory will slow the machine down.

Hopefully an answer of sorts is better than none at all.