First you need to check that all of the memory specifications are supported by this motherboard ( voltage, size and speeds)
If the memory is compatible, you can try updating your BIOS.
If the problem continues you can test one memory stick at the time, make sure that all of the memory that you are using has the same specifications.
I tried putting in each stick of memory as you suggested and it fails after I try to insert in the third stick of memory. I believe the memory is compatible. It's a Corsair Value Select brand and it's a 667mhz DDR2 PC5300 type chick. The previous 1G of memory was the same brand and the current 2 sticks that are working in the machine are also the same brand and type of memory. I checked my BIOS and it's running version SN94510J.86A so I'm at a loss as to what to try next. I'm assuming this is the latest version of the BIOS. Do you have any suggestions on how to diagnose the problem?