My PowerMac G5 isn't seeing all the RAM for some reason. I have just installed 8x 1GB modules and for some reason it does not see DIMM0, DIMM1, DIMM4, DIMM5. All others are seen. These are identical and brand new RAM modules from Samsung. Any ideas? Is this a firmware problem or do I need to re-seat all the RAM and see if that works? Hopefully this is not a sign of something more serious to come.