#6 Unable to load Add-In to VS.NET

[Tim Q.]

From within VS.NET (I have Enterprise Architect 2003, and
Microsoft .NET framework 1.1), I'm unable to load the
TestDriven.NET Add-In. In other words, when I'm in
VS.NET, and go to Tools->Add-in Manager, and check the
box next to 'TestDriven.NET 1.0.915.0', I get a popup with
the following message:

The Add-In 'TestDriven.NET 1.0.915.0' failed to load or
caused an exception.
Error Message <Unknown Error>
Error Number: 80131604

Thanks!