I'm having similar issues. I was the one that inadvertently upgraded 10.6.3 to 10.6.5 using the Software Update instead. But after much work I reverted the system back down to 10.6.3 and upgraded following the directions very carefully. And upon rebooting, it freezes up right after the apple logo goes away. The screen blanks as if it's preparing to go to Finder but then it pops up a blank grey screen and it's stuck. No hard drive activity whatsoever.
Booting using -v -f DOES work. It boots into the system. However after a few hours of being idle, the screen blanks and the computer is frozen. This wasn't the case with 10.6.3. In 10.6.3 if you click the mouse or the keyboard the computer will wake up. It's just a black screen.
Any ideas?? I tried installing DanielFo's 10.6.5 package several times but it does not successfully reboot. I have to F8 and then go to -v -f and then after that it works for a while but freezes up at some point if the machine is idle.
right now, what i did was that i re-installed OS X according to the instructions. however, after the installation it gets stuck at the default background but nothing appears somehow. no dock, no task bar etc..... i reboot and the same issue persists despite two re-installs. could the combo install messed it up? i have the 10.6.3 default snow leopard retail...
and i also used the USB install mode, could that have been the cause?