Why is it, I wonder, some work and some don't? A bad installation DVD, perhaps? One is recommended to verify it first, before installation. Otherwise, I very puzzled, as I'm sure you must be. /Bill
Bill, I work in higher ed IT (Macs) and install system updates and software on multiple computers routinely. Every now and then one or two computers will behave differently than the rest, though all models may be the same. This usually indicates hardware issues, or perhaps just isolated bad voodoo. I feel bad for home users who have only one computer and don't have the overview that you get in a lab, where bad hardware becomes obvious quickly.
Before upgrading to Leopard I read all the horror stories about people bluescreening for hours on end. In my experience, the blue screen lasted maybe a minute. So another set of factors may be in play that helps cause problems, and that is users hacking about in their systems and/or not doing proper maintenance. I generally don't have all of these bad problems, unless genuine bugs exist (and of course they do, both in the OS and third-party apps).
--Writing to you using Leopard on an unsupported G4/533DP! Originally installed via an iMac G5 with the G4 in target mode. I just upgraded my Mac Pro in the office to Leopard.