Software Update says "no new updates" when programs tell me there are

When I open iTunes and iPhoto (and some others) I'm told that there are new versions/updates available. When asked whether I want to download them now, I click YES and it takes me to Software Update (as usual). However, when Software Update launches and searches for updates, it tells me that there are no new updates available. Here are the steps I've taken so far:

Reset manual settings (?? all I know is the Apple guy told me to restart the computer holding Command, Option, P and R I think)
Repaired permissions
Repaired disk (worked somewhat because it showed me the available updates but when I went to download them they said the server was unreachable and when I re-opened Software Update the updates were no longer visible)

Does anyone have any other brilliant ideas???

THANKS!

PS: The last successful update was on March 20 2010 with Safari 4.0.5 and a Digital Camera update.