Hello, I come to you with this problem that has been giving me grief for the past few days. I am attempting to upgrade the RAM on my computer from 256mB to 512 mB. Current there are two 128 sticks in there. If I add a 256 stick in a third slot, the pc will crash within two minutes. If I take out the 128's and leave just the 256 in, the pc works fine. The pc works fine with the two 128's by themselves. They are all SDRAM PC 133's. I have a Gateway with a Microstar MS-6330 K7T-Pro motherboard. (1.6 ghz). The max RAM capacity is 1.5 gb. 300W power supply (new) Any ideas?