Since I haven't been able to get help on this forum: http://forums.macrumors.com/showthread.php?t=96378&page=1&pp=20 (probably b/c most people do not want to read 2 pages to get to my problem) I'm posting this here. Yesterday I updated my PB via software update to 10.3.6. All is well with my PB. Today I tried updating my iMac G5.....after the download finished it started installing and optimizing (via software update). It reached 58% and crashed. A rectangular black transparent window appeared and told me I needed to restart. It then gave me directions for powering off my iMac with the power button. So I did and restarted. When trying to start up it stays on the grey screen. At first it would have the circular loading icon on there but now that does not even show up. I've left it going for hours now. I downloaded the 10.3.6 self installer onto my PB....loaded my iMac via FW target mode and installed it onto the iMac. Still does not work. I've repaired permissions and repaired disk...still nothing. I always repair permissions before and after any installs. This is the first time I've had such a problem with an Apple update. Any ideas? Thanks!