I forgot to include a configuration file when I committed the changes.
Add an app.config file to the root of the Agathas.Storefront.Acceptance.Tests project with the following content...
<?xml version="1.0" encoding="utf-8"?>
<section name="TestRunner" type="System.Configuration.NameValueSectionHandler"/>
<!-- Valid values are STA,MTA. Others ignored. -->
<add key="ApartmentState" value="STA" />
You can read why we need to add this file here http://watin.sourceforge.net/apartme...nfo.html#nunit
Let me know if this doesn't solve your problem.