Remove APE before insalling 10.5

There are known issues with Unsanity's APE extension and 10.5. Remove it before upgrading to 10.5.

You may not realize you have APE - Logitech's mouse driver is known to use it, and AudioHijack Pro's Instant hijack is also known to use it.

If you are getting the blue screen and no loginwindow, you can nuke APE without a reinstall with the following steps:

1. Boot into single user mode by holding Apple+S on startup


2. fsck -fy /


3. /sbin/mount -uw /


4. rm -rf /Library/Preference Panes/Application Enhancer.prefpane /Library/Frameworks/Application Enhancer.framework /System/Library/SystemConfiguration/Application Enhancer.bundle /Library/Preferences/com.unsanity.ape.plist


5. sync;shutdown -r now

Edit
John Gruber has more background on this in an article he wrote on Daring Fireball here and Apple posted a KB article about this here.