Hi, I installed 2 x 2gb sticks of ram with the mac ram that was already installed in the computer. I checked to see if the computer recognized the ram and it did recognize it had 6gb installed. I went to check it again today and noticed that it stated that i had only 4gb installed. I went to check the memory set up in "about this mac" option and clicked memory and noticed it recognized the 4 dimm risers that had the memory installed but the 2gb dimms were stated at 1gb each. I uninstalled them and installed them again and checked it again where it stated 6gb of ram was installed. I thought i solved it but i just went to check it again and it is again stating i only have 4gb installed ( 4 dimm risers with 1gb installed). Any information would greatly be appreciated.