Debugging Outlook 2010 Add-ins with Visual Studio 2010

I’m using the Office 2010 RC and VS 2010 RC1.
There is an odd change in behaviour when trying to step into an Outlook 2010 Add-in from VS2010. Using VS2008, I set Outlook as the external program to start, set breakpoints and hit F5. The breakpoints were hit as expected. I upgraded the project to VS2010 but when trying to debug, Outlook started without hitting the breakpoints. I could see the Add-in loading and it was visible after Outlook started.
I was lucky enough to get a tip from a colleague that if I set the Start Action to Start project rather then Start external program, then it worked fine. We’re still trying to determine if this is an intended change in behaviour or a bug. I’d call it a bug, but this is my first attempt at writing an Office Add-in, so I’ve not been on any aliases etc to see if this was ever mentioned.
This may affect other Office applications, but I’ve not had a chance to investigate it further.
[UPDATE: Answers from Misha here: http://blogs.msdn.com/mshneer/archive/2010/03/19/com-shim-wizards-for-vs-2010.aspx]

Source: http://freetodev.wordpress.com/2010/03/05/debugging-outlook-2010-add-ins-with-visual-studio-2010/