This lovely little probelm just happened to me on my late 2011 15" MBP. Though I was able to boot right away in safe mode, and Verbose mode didn't show any obvious errors. I ran some automated maintenence via an app called Onyx and rebooted. The boot process took about 4 minutes (as opposed to the normal 25 seconds), but I was finally able to login normally.
I'm not entirely sure what is causing this problem, though the last time I had any simillar boot issues was a few months ago which ended up being the result of dual booting a cracked copy of Windows 7 (the nature of the crack affects the way the computer boots). I have since been running OSX and a legit copy of Win7 without incident for about 2 months.
Hi Will !
Thanks for the reply
Yeah OnyX is the must have utility for Mac OS X !!!
So you'd ran the "Maintenance" process with "repare permissions" or "Automation" then execute "Repare permissions" & "maintenance scripts" ? (i'd never used this last feature yet)
The 2 macbooks where i've seen this issue were using official Lion & without a Windows OS.
But with a cracked windows, you'd taken the risk to have a Macbook Pro with a big flu ! Ahah
Ok, I think the 1st restart slows because the Automation may empty every caches like it do in the "Cleaning" tab.
But it's only on the 1st restart !
It seems that Apple got a truly big problem with laptops & Lion OS...
Thanks for the help !
Using "Safe Mode" boot & launch Onyx's "Maintenance" in "Automation" tab is a fine way to solve temporary the problem.
For me, it never appared twice on same Macbook Pro but... should wait & see