I bought 2 2gb sticks of matched RAM for my 2.8ghz 8-core Mac Pro. When I finished the install About Mac said I had 6 gb. This was 5 weeks ago. I just checked About Mac and it said I have 4gb now. I don't know when the RAM stopped being recognized as 2gb sticks but it is gone now. System Profiler says that I have four 1 gb sticks. Not true, not possible. They are installed properly and as I said the RAM was there at one point. Any ideas?