Not sure why, but today when I selected "Check for New Software" from the Apple Menu, Software Update started checking and does not proceed past that step. I've included a screenshot to show exactly where it's stuck.
Sounds like a corrupted preference file. Go to ~users/library/preferences. Locate software update plist and trash it. Logout/Login. The OS will create a new preference plist file and then retry software update. Regards, hpr3
Well, I appreciate all of your help, everyone. It turns out, a simple restart fixed. I suppose it's a good thing that this will be here in case anyone else encounters this problem, but I have egg on my face, now don't I. Thanks again.