Here's a good article to read BEFORE you attempt to upgrade to 10.5: http://www.macfixit.com/article.php?story=20071026082852658

In an article a few days ago, we mentioned that "For most users, a basic upgrade [where the installer merges Leopard directly with your existing files] will suffice". But that doesn't mean we recommend it. We don't. In fact, there is a school of thought that says you should never, never, never do a "basic upgrade" installation - that such an installation is, indeed, the root of all evil. Not only do you inherit a lot of old stuff that may be incompatible, but the algorithm whereby the installer "merges" your existing system with the new one is not reliable. The majority of troubles reported in MacFixIt may well stem from having done this sort of installation.

Yeah Boyd, I was reading several posts on the Apple discussion forums and one of the culprits interfering with the upgrade is called APE by Unsanity. Seems they use a private API call which Apple has said is a no-no. This API call is gone in Leopard. Still others reported some interference from DIVX.

Archive and install method solved about 90% of the basic upgrade failures.

-gb-

Yeah Boyd, I was reading several posts on the Apple discussion forums and one of the culprits interfering with the upgrade is called APE by Unsanity. Seems they use a private API call which Apple has said is a no-no. This API call is gone in Leopard. Still others reported some interference from DIVX.

Archive and install method solved about 90% of the basic upgrade failures.

-gb-

A simple wipe and re-install is all I need.

Of course, I am blessed with many drives and only have programs on my main drive. I can afford to wipe a drive and not loose anything.