UPDATE: I go to dinner and all hell breaks loose. Sorry for the bogus info. My bad. I should have checked this out first. Apparently, this combo update is not good — it causes kernel panics. Here’s a legit link to the 10.6.5 combo update on Apple’s site: https://support.apple.com/kb/DL1324
Here’s the hidden URL where you can download the Mac OS X 10.6.5 Combo update. This combo update is not visible on Apple.com
Some folks think it’s usually better for your OS to install the combo update. From what we understand, the combo update does a more complete update than incremental updates applied through OS X’s Software Update. For example, system glitches caused by earier updates may be fixed because the combo update reinstalls everything that was included in previous updates (in this case, everything in 10.6.1 through 10.6.5).
It can also help avoid update headaches, we’re told.
Thanks Roman Zavřel of Letem Světem Applem.