To the best of my knowledge, the *.dnn file is known as the "manifest file."  When I build a module, I am given instruction to install it using the the "manifest file."  When I attempt to do so, I receive this message, "Invalid File Extension For Custom Module Slate.dnn."  Just to be sure I used the definition validator to ensure that it was okay, and the validation checked out.  Unless I misunderstand, the installation of the module through the use of the manifest file is what ensures that the project gets plugged in to all of the right places; i.e. if it doesn't happen, I won't be able to get SlateView.ascx to show up in DesktopModules, and will therefore never be able to define a soure for my module controls.  Any suggestions, or something I'm obviously missing?

The module I am trying to install is one that I just initialized in VS2008, using the New Project Web DotNetNuke Compiled Module template.  I chose "Add to Solution" but of course the files are still in their own directory as a separate project within the solution.  I followed the directions provided on the intro page for the DotNetNuke Module template; the step that is failing reads "Browse to the Host/Module Definitions page and select Add Module. In the drop-down combo at the top of the page select the Manifest file for your new module and click Install."  It didn't mention anything about a .zip, but I could zip up the directory containing the module's files... though if I was supposed to do that, I would hope that it would've been included in the instructions.  Any feedback?

I have the same issue using VS2005 C#.  As this is a development box I changed the allowed extensions to include dnn.  However, this did not work.
One other issue with c# is that creating a new project it fails as it attempts to use C:\Program Files\MSBuild\Microsoft\VisualStudio\v9.0 rather than v8.
 If you need to zip up various lumps of code to get this to work what ones do we zip?