Account Settings screen broken

After installing VS SP1, I noticed that the pretty theme buttons in Outlook
had reverted to the Win 2000 style, but functionality was the same (I've been
using Outlook like this for weeks now, and send/receive/etc seems fine).

Today I went to add a new email account, and I found that the Account
Settings window shows as blank (you can also see what I mean by flat style
buttons):

http://www.280z28.org/images/office2...tsettings1.png

When I click in the box that should be showing the list of accounts, it
changes to this view, as if I just unselected something:

http://www.280z28.org/images/office2...tsettings2.png

I uninstalled and reinstalled Office 2007 with the same result. Then I ran
Office Diagnostics and it came up clean:

http://www.280z28.org/images/office2...officediag.png

Any ideas how I can resolve this?