pc3200 hangups and reboots

[ran]

I replaced Mushkin double sided pc3200 1 GB with 2 GB of the same. Intel D865 will let me into BIOS and it is there. this board has no advanced BIOS to make changes to MB. I boots fine and fast, but only stays up for a few minutes. new MB is Mushkin silverline pc3200/DDR400 thanks