Yesterday, Apple released the 10.5.6 update for Mac OS X, Leopard - and, as usual, problems are surfacing. Of course, some people have problems that most others don't. As Chief Dan George said to Dustin Hoffman in Little Big Man, "Sometimes the magic works. Sometimes it doesn't."
Most problems seem to arise when installing the Delta upgrade downloaded from Software Update: Numerous users found that update to be problematic, but the full Combo update available from Apple's website ran smoothly.
Over at MacInTouch, readers report a grab bag of difficulties, including their Macs hanging during installation or post-update rebooting, dropped AirPort and wired network connections, and audio "pops" upon restart.
Problems with Mail.app after a 10.5.6 installation seem especially notable, including the app refusing to quit, failing to connect or crashing while attempting to connect to a previously accessible mail server, messages with attachments causing the app to crash, and all alert noises going silent when - or so the MacInTouch poster claims - "the preferences are set in a way that it should."
The winning gotcha on MacInTouch, however, comes from one poster who reports that the 10.5.6 update "just made my 24-inch iMac a totally useless brick. Now have a white screen, beeps 3 times, paused about 3 seconds, then repeats beeps." Unfortunately, he'll soon find out that a three-beep iMac startup code usually means bad RAM.
MacFixIt has also weighed in on 10.5.6 problems, noting many of the same reported by MacInTouch and offering a few recommended solutions to Mail and AirPort problems.
Here at The Reg we've updated a Dual 2.7GHz Power Mac G5 and a Dual 2.8GHz quad-core Mac Pro and have had only minor problems with both. After the installation proceeded without a hitch on the former, the reboot hung for about five minutes. After the fan achieved wind tunnel-level velocity and noise, we forced a shutdown by holding down the power switch. The next reboot proceeded without a hitch.
The Mac Pro wouldn't let a recently added admin account install the update, claiming that the account did not "have appropriate access privileges." Merely switching to the original admin account allowed the update. After the update - which was glitch-free - concluded, we only noticed one annoyance: The desktop image was zoomed far larger than it had been and had been switched to the Tile setting in System Preferences. Resetting that preference deniggled that niggle.
Overall, the 10.5.6 rough spots are about par for the course for an Apple OS upgrade. However, we at The Reg still recommend that before you attempt the 10.5.6 update - or any update, for that matter - you should create a bootable backup of your entire system, including files and apps. Yes, doing so a time-consuming pain in the wazoo, but as your dear mum used to say, "Better safe than sorry."
It's also good digital hygiene to repair permissions using Disk Utility before updating - doing so may not prevent problems, but it certainly can't hurt. And if you're truly paranoid - or careful, depending upon how you'd prefer to characterize yourself - before you perform the update, reboot in Safe Mode by holding down the Shift key immediately after you hear the startup chime and continuing to hold it until the spinning progress indicator appears beneath the Apple logo - and be prepared to wait, since when starting in Safe Mode your Mac will run a full fsck (file-system check) of your startup volume before commencing the boot process.
If you're one of the unlucky few and you experience problems even after taking our advised precautions, remember that a simple reboot is always your best first troubleshooting move [File that statement under "Duh..." - Ed]. If an app remain squirrelly after that, trash its plist file in both Library/Preferences and ~/Library/Preferences and relaunch the app. It's also a good idea to try disabling Mail add-ons - although they may have worked perfectly in 10.5.5, 10.5.6 may have angered them. Finally, in some cases, reseting the SMU can make all well again (find out how to do so for your Mac here), especially if your problems are USB-related.
With any luck at all, you'll get everything sorted out - until 10.5.7 is released. ®