P4VMM2 with power video crash

I have problem with the ECS P4VMM2 mobo using DDR 266 SDRAM. When I used SDRAM PC 100 sticks in DIMM1 instead of the DDR266 memory in the DDR slots, I can get the mobo to work.
After jumpering the J2/J3 pins to short the pins and setting the JP1 pins to open, I installed one stick of DDR266 SDRAM (Kingston ValueRAM 512MB 184-Pin DDR SDRAM DDR 266 (PC 2100) Desktop Memory Model KVR266X64C25/512). The system would boot up and stay up for about a minute or two and then the screen would freeze with bar patterns on the screen. I could sometime reboot to start again, only to have it freeze again. What SDRAM Freq am I supposed to set in the BIOS? Or am I missing something really fundamental here, like the mobo won't support the 266 SDRAM. Is this a bus speed issue and how do I find out what the bus speed is for the board I have? Or is there a problem with the DDR circuitry on the mobo? I have one other "similar" board as this one that does support the DDR266 sticks. Any help appreciated. THanks