I deployed a large ASP.net application on IIS 7 ported from IIS 6. There are certain parts of the application, unfortunately, that have Atlas not converted to Ajax but work on .Net framework 2.0 running on IIS 6.0. The application works just fine. On IIS 7, the parts that still have Atlas implementation...

This is due to a non-essential piece of Atlas having an issue with the new ASP.NET Integration mode. This is fixed in a subsequent release by removing the module from the Atlas web.config file (you probably got it when you migrated the Atlas configuration, bringing this module over from the httpModules...