Following up on the 10.5.6 upgrade: The most common issue people seemed to have upgrading to Leopard 10.5.6 was that the install would get stuck at 'configuring installation'. It happened to me, and judging by the Apple support boards and others, it was a pretty widespread bug. We reported the problem Tuesday.

Apple has now responded and acknowledged the issue with a support note. It says that the problem can be caused by getting an update that "was only partially downloaded". Of course, what was not explained was how Apple provided only a partial update, and why and how this got past Apple QA?

For most people, installing the combo update solves the install freeze. Apple is recommending that people use Software Update, so most likely the bad package has been removed from the servers. There are still some nagging issues with Mail, mounting network volumes, Safari, and the other all too usual issues following an OS update.

Of course, for many, the update went just fine.

Thanks to all who wrote in and shared their experiences.

Apple support boards are filling up with reports from frustrated Mac OS X 10.5.6 upgraders. The most common complaint seems to be that the update stops in the middle and freezes. Here are some sample comments:

• I tried to upgrade to 10.5.6 yesterday and I left the computer on to do the upgrade while I went back to work. When I came back, it has the normal window up that says "configuring installation" and from there it just starts and hangs.
• I have just downloaded the latest update (10.5.6) and then rebooted my iMac, next the software Update box appeared on screen as usual, saying: Installing 1 item, configuring Installation. Then the Blue progress bar started to move to the right, went about 1/4 of an inch and stopped there, I left the iMac running for two hours and the progress blue bar had not moved.
• My Mac gets to preparing installation then nothing... Left it there all night in case I was being impatient but this morning still preparing install?

My own experience was similar. My Mac Pro upgraded just fine. My mid-2007 MacBook Pro froze on the 'configuring installation' screen. I went back to the Apple site and downloaded the combo update (which many frontline Mac techs recommend as a best practice for all system upgrades, despite the 3x larger file size) and installed that after booting from a backup USB drive. After that, everything was fine. Many upgraders, however, may not know to try that approach, and those with problems will keep Apple support techs quite busy today.

Some people noticed that the upgrade may not fully download [via MacInTouch] yet the installation proceeded anyway. If widespread, that would be a pretty serious problem, and Apple needs to do some diligent investigation.

There was a smattering of other problems. Some people saw mail crashes, network issues, and a lot of the usual complaints that seem to afflict a handful of users. At this point, it is hard to tell if this update was better or worse than previous ones, but clearly a lot of people got stuck along the way.