Office 2008 won't detect new updates

Hi there,

I just installed Office 2008 on Mac OS X 10.5.8, but I can't seem to get the system to detect Office updates; it won't even detect Office 2008 SP1. Every time I try to get Office to detect new updates, it gives me the following message:

There are no updates available for your Microsoft software at this time. Please check again later.

...which is funny because there obviously ARE new updates. I know that I can simply download the updates manually from the Microsoft support site (which I did to install SP1), but I am curious as to what the source of the problem is, and if it can be fixed. I have had Office 2008 installed on the same machine before, but had to reinstall it. Before reinstalling, it detected updates just fine. Now it won't!

I also installed the most recent version of Microsoft Autoupdate 2.1.1, but it didn't seem to work. Any ideas?

Thanks!