I have a 2.66 quad core 2009 Mac Pro. Running 10.6.2. I see weird behavior in the Activity Monitor. The "% idle" number jumps from 49% to 61% to 99% (but usually stays around 49%), when I'm actually 99% idle. The "% user" and "% system" just don't add up to "% idle." Does anyone else see this? I'm wondering if it has anything to do with the RAM I just installed, or if this is a coincidence.