HT1338: OS X: Updating OS X and Mac App Store appsLearn about OS X: Updating OS X and Mac App Store apps
Currently Being ModeratedOct 10, 2012 3:47 PM (in response to jchair)
Try going to the Apple support site ,and downloading them from there, as opposed to using Software update. You can use software update to find out what updates are available, write them down then go to Apple support and type in the search window, application and version, and download them, and install manually. I've found this to be helpful in the past, hopefully this might help you. Try it one at a time.
Currently Being ModeratedOct 10, 2012 4:09 PM (in response to jchair)
I think you should take a look at this link. http://support.apple.com/kb/HT1338?viewlocale=en_US
I don't have a Macbook Pro so I cannot anticipate the problem but I do think there is something wrong that needs looking into for even if the manual download works, the other option doesn't ... and it should.
Currently Being ModeratedOct 10, 2012 9:06 PM (in response to jchair)
explains what might be going on.
I noted when this happened on my wife's iMac, one of the updates listed was an update to Software Update itself. Probably to fix this very problem. But it wasn't being applied due to Software Update itself not working.
I considered two solutions.
(1) Uncheck all the updates except that one update to Software Update. Then after fixing Software Update, apply all the other updates remaining. I did NOT try this approach.
(2) Download and install the "combo update" for 10.6 -- from here
I decided to try solution #2. It's a large download, 1 GB, but the whole process took less than 15 minutes. The "combo" update checks and reapplies every update since the beginning of 10.6, so if something is missing or amiss, it gets filled in. It's done manually, by downloading the update, opening the .dmg file, and running the update. When I did this, it fixed the Software Update issue because I then reran Software Update and additional, new updates were found and they all installed fine. Software Update was working as it should. I then ran it a third time and some additional ones were found, also then successfully applied. Finally, no new updates were found by Software Update, which mean everything is up to date.
I can't be sure if your issue is the same as mine (the bug in the CNET article above) but I'm guessing that the combo update will resolve your issue.