I'm using this solution to modify the MSI to include a checkbox for user to decide whether s/he wants to launch the application after setup exits.
Although everything works just fine, what I noticed was the application was not able to use any COM DLL's registered during the setup when it was auto launched. The app works perfectly when launched again from start menu.
I have tested it on Windows XP and Windows 7.
The COM DLL's have been marked as self registering dll's in the setup project.