Try running Apple Hardware Test. When your computer detects bad RAM, it will essentially turn it off while the computer is booting. Of course, the computer can only detect about 5% of bad RAM to begin with; most RAM problems are intermittent and extremely difficult to detect. Usually, you only see them as repeated kernel panics, hard drive directory corruption, crashes and freezes, etc. Alan Vonderhaar <alvonder at fuse.net> writes: > Here's a curiosity -- > Since upgrading to latest build of 10.2.8, my Ti800 shows only 768M of > RAM, as opposed to the 1 Gig that's in there. It shows the top slot as > 256M, sted 512. Who stole my RAM?