Software Updates app not showing new updates

Question

Hi,
The Software Updates app is not showing new updates. I always get "No Updates Available".  For instance, I run 10.8.3 but 10.8.4 is not showing up. I run iTunes 10.0.2 and when I open it  I get messages asking me to update to newer versions but they are never showing up in the Software Updates app. I played with the Software Updates app preference files but it did not change anything. Any idea on why the Software Updates app is not working properly.
Thanks

Answer 1

Read this whole message before doing anything.
Back up all data. Quit the App Store application if it’s running. Test after each of the following steps until the problem is resolved.
Step 1
Triple-click the line below to select it:
/Library/Updates
Right-click or control-click the highlighted line and select
Services ▹ Reveal
from the contextual menu. A Finder window should open with a folder selected. Move the contents of the selected folder to the Trash. You may be prompted for your administrator password.
Step 2
Do as in Step 1 with this line:
/Library/Preferences/com.apple.SoftwareUpdate.plist
If there's no change, quit the App Store and restore the file you moved from your backup, overwriting the one that may have been created in its place. Otherwise, recreate your settings in the Software Update preference pane.
Step 3
Hold down the option key and select
Go ▹ Library
from the Finder menu bar. Move the following items from the Library folder to the Trash (some may not exist):
Caches/com.apple.SoftwareUpdate
Preferences/com.apple.SoftwareUpdate.plist
Preferences/ByHost/com.apple.SoftwareUpdate.*.plist
Saved Application State/com.apple.SoftwareUpdate.savedState
Here, "*" stand for a long string of letters, numbers, and dashes.
Step 4
If you still have problems, quit the App Store again.
Triple-click anywhere in the line below to select it:
open $TMPDIR../C
Copy the selected text to the Clipboard (command-C).
Launch the Terminal application in any of the following ways:
☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)
☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.
☞ Open LaunchPad. Click Utilities, then Terminal in the icon grid.
Paste into the Terminal window (command-V). A folder should open. Inside that folder, there may be a subfolder with the name "com.apple.SoftwareUpdate". If so, delete it. You can then quit Terminal.