It has been a frustrating few days getting 'Test With... Debugger' working again when any of the Beta2 products are installed (VS2005 or Express). It turns out there are two completely independent issues. One breaks debugging in VS2003 when installed side-by-side with VS2005. The other appears to be an issue with the VS2005 debugger itself (it crashes when it can't find one of the PDB files). I've created a new installer with workarounds for both of these issue.
The other day I mentioned a way to get debugging working again in VS2003 (by adding a 'bindingRedirect' to Visual Studio's 'devenv.exe.config' file). Unfortunately this has side effects of its own and prevents the command bar buttons from being installed on a fresh install of TestDriven.NET. Everything worked just fine assuming TD.NET had already been installed. If you made this change, I would recommend rolling it back and installing the new version.
There are a couple of other changes worth mentioning. I've updated the 'QualityTools' test runner so that is works with the latest VSTS 'Test Project's. I've also improved the plug-in model for test runners. You'll need this version if you want to use the version of MbUnit on Tigris with TD.NET. Everything is there to build your own compatible MbUnit installer (using MSBuild + Wix).
You can find the new build here. Please let me know how you get on so I know when to make a higher profile announcement.