Startup issues

Since updating the EFI and upgrading to 10.8.2 I have now twice tried not being able to startup correctly. My MBA (mid-2012) is turned off, and I turn it on. It goes to grey screen with the Apple Logo, and I get the cursor. However, it doesn't get any further.

I then turn it off, and start it back up into safe mode (shift), and after having done that I can just restart, and it all works again into a normal startup.

Anyone

 

I have done of all of these things. I installed YASU and cleaned all out. I verified the disk, and I deleted the desktop plist file. The only thing I didn't do was clean out the launch daemons. However, I still have this "little" annoying thing that my MacBook Air sometimes (about once a day) does not start up regularly. And when it hangs on the boot, I turn it off, and start it up in "Safe Mode". I di not even log into OSX, I just get to the login screen, and restart. It all works fine then.

The only thing I can sometimes see as a pattern, but not always, is that this occurs when I get to work, or when I come home. At work my MBA access one WiFi network, and at home it accesses another one (of course). That is the only thing I somewhat can spot as a pattern - changing WiFi networks.

Anyone?