WSUS only installs a few updates on clients

I just installed WSUS on my server a few weeks ago and am in the learning phase. It is running on 2003 Server Standard Edition and I have applied the automatic update settings to all PCs on my LAN using group policy. I know the policy is taking effect because as soon as I implemented the group policy clients started installing updates, plus I can see all the computers listed in the WSUS admin page under the computers tab.

I have one client on the bench that I'm testing it out with. I did a fresh install of Windows 2000, then updated it with SP4 and IE6. When I joined it to my domain, I checked automatic updates under control panel and it was greyed out, so I know the automatic updates policy is in effect. I can also see the computer listed in WSUS, but when I run the status of computers report in WSUS, it shows 13 updates installed on this computer, but 98 needed.

So basically what I want to find out is why did it only install 13 updates when it says it needs 98 more? Is there some way to force it to install the rest of the updates, or can I at least check to see if automatic updates is even doing anything on this computer?