First let me thank you for your comments nightsoul. I have been grappling with this issue for a while. I am using the Visual Studio 2005 Professional. My IT department did reinstall the OS and all my stuff on my system not that long ago. When my IT department did this they misnamed my machine, they then corrected my machine name after I installed Visual Studio, SQL Server 2005 Developer Edition, and all my tools and utilities (Red-Gate Professional Toolbelt, SourceGear Vault, and so on).
Before this, everything worked fine up to 4.4.1 (which still works for me). I did use Vaults diff tool to look at the different vstemplate files included in the DotNetNuke.zip file and noticed that the reference to the DotNetNuke.webproj file - while included in the zip - was not in the vstemplate itself; whereas it is contained in the 4.4.1 DotNetNuke.vstemplate file.
So I changed the vstemplate file to include the DotNetNuke.webproj file and inserted it into the DotNetNuke.zip file, uninstalled everything, and reinstalled the templates using the DotNetNuke.vsi installer. But no love. The DotNetNuke Web Application Framework and all the other templates do not show up in Visual Studio.
Why would the 4.4.1 installer work and the 4.5.1 installer not work if it had something to do with my installation of Visual Studio?
Finally, I installed the 4.4.1 starterkit and checked VS. The DotNetNuke Web Application Framework shows up fine. I tehn copied the DotNetNuke.zip file from the 4.5.1 starterkit into the ProjectTemplates/VisualBasic folder and checked VS again. The DotNetNuke Web Application Framework entry disappeared! This definately has something to do with the DotNetNuke.zip file.
Whe million dollar question is what.
Cheers!