Software Updater Freezes

I have a PPC mac mini with Leopard installed. The last software update was in approximately April. I went into iTunes and was prompted that there was a later version. I went into the Apple Software Updater, but it hangs about a third of the way through the process. I can 'cancel' the update, i.e. not beach ball, but it won't finish and display the list of items to update.

I searched the forum and one suggestion was to delete the contents of the Library/Updates folder. This has not resolved the issue.

How long can an update search take? I am waiting ~20 minutes, which is much longer than I have had to wait in the past.

Any ideas?

Thanks,