If you’re thinking of updating your OS X 10.6.5 system to the recently-published 10.6.6 update: please think twice about it, or at least, take a full backup of your system first.
I’ve never had a major problem updating my previous MacBook or my 2010-model MacBook Pro to minor 10.5.x or 10.6.x versions, before yesterday, that is: after installing the 10.6.6 update without a hitch, and installing the subsequent updates after that upgrade (which included an update to Apple Remote Desktop Agent), my MacBook Pro can no longer boot into Snow Leopard. The disk is fine, permissions are fine, but a normal boot attempt won’t get past the grey Apple logo and spinning progress wheel. Safe boots do the same, and verbose boots stop while loading networking drivers, and the ‘vmnet’ VMWare virtual adapter device in particular. The last boot messages that get posted are:
vmnet: Invalidating peer info for hub: 0, port: 0 vmnet: VNetUser-IfFree: freeing user If at [mem-address]
I’ve started a thread on this over at Apple’s Discussion forums, and it’s gotten a fair amount of attention, as well as an alarming number of “me too” replies so far, but no solutions. Other reports say their systems stop booting while the Airport device loads. And still others say they’ve upgraded with no problem at all.
I’ve just run Disk Utility via the OS X installation disc (again) and while repairing permissions, got this “warning”:
SUID file "System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/MacOS/ARDAgent" has been modified and will not be repaired.
I am fairly certain this is related to the boot problem: I’ve run permission repair several times now after multiple disc boots, and this is now the only feedback that gets returned, but it’s returned consistently.
Update: well, really, there isn’t much of an update. I called Apple Support. They acknowledged that many people are reporting similar issues with this update, and I wasted an hour on some rather unhelpful questions and suggestions (at one point, I was assured, multiple times, that my PRAM and NVRAM would be reset if I held down a keystroke combination while the machine was turned off without powering it on. No, I’m not exaggerating.). Ultimately, the official recommendation was to completely wipe out my OS X partition and re-install Snow Leopard. All I did was install official Apple updates from the official OTA Apple distribution channels as prompted by the operating system. I guess I wasn’t truly surprised by the recommendation, but if that’s the advice that comes with a full warranty and the additional cost of Apple Care, the additional cost certainly doesn’t seem justified.