Since updating to OS X 10.7.4, I can't access either Preview or iPhoto.
The blue light comes on, and the icons bounce, but the applications don't open and you can't use them. Software update says that everything is up to date and there is nothing left to update. Nothing at Apple Support in the troubleshooter section offers any help.
It is iPhoto version 9.3
and Preview version 5.5.2
The only other software I've downloaded is the latest Office 2011 for Mac, but I put that on the computer AFTER the problem had already started.