Grey screen with Apple logo and spinning gear MBP OS X Mountain Lion

This is how it started:

I was unable to connect to the iMac over the wireless network at my home for a couple weeks, so finally I decided to try and remedy the situation. I found an article on here about resetting AFP via Terminal, and after the first command was entered, the MBP restarted immediately to the grey screen with Apple logo and spinning gear - it would not advance beyond that point.

Initially trying to find out why, I restared in Verbose mode and it gets stuck on (and never progresses past):

BootCacheControl: Unable to open /var/db/BootCache.playlist: 2 No such file or directory

Here are things I have tried to remedy this:

1. rebooted in Single User Mode and run fsck -y (result - disk fine)

2. rebooted in Safe Mode; gets stuck on same grey screen. booting in Verbose Safe Mode shows it gets stuck on the same line.

2. rebooted in Recovery Mode and run Repair Permissions in Disk Utility (again, fine)

3. rebooted in Recovery Mode and run Verify and Repair Disk (also, fine)

4. rebooted in Recovery Mode and reinstalled Mountain Lion system software - two times.

Still facing the exact same issue.

Hardware: MacBook Pro 15-inch, Mid 2010 (MacBookPro6,2)

Software: OS X 10.8.4 Mountain Lion