Not a single cocoa app opening after the 10.5.6 update

Question

I have a serious problem. Not a single cocoa application (Safari, Mail, Pages, etc.) will open for me. It will bounce in the dock and then crash. The Carbon apps are fine (iTunes, FFox, Finder) I have no idea why. Any ideas?

Answer 1

I agree that repairing permissions before & after installing an update is more of a voodoo-like ritual than sound advice based solidly on fact.
Once, in the early days of OS X, it was not entirely uncommon for certain non-Apple product installers to set permissions to unusual values to facilitate installing some app & then fail to reset them afterwards, or to reset some file permissions they should not. This at least explains why the advice to repair permissions after an update became common -- some users have an unfortunate habit of thinking that what fixes one specific issue might have some mysterious ability to fix others, so they add it to a ritualistic formula designed to prevent any problems, whether still applicable to the current software climate or not.
Just to remove any lingering doubt about this, users should note that AFAIK, no Apple product installer ever has been shown to do this & current OS updaters certainly don't. As mentioned, some users confuse innocuous warnings with mis-set permissions, which seems to perpetuate the idea that the OS update installers frequently cause permissions problems, but this is a misconception.
What is worth doing prior to installing an OS update is Disk Utility's "Verify Disk" test, & if it shows anything is amiss, rebooting from the installer DVD & running the "Repair Disk" step. This is because disk file system problems can cause an install to fail, often by corrupting essential OS files.