I too am having a problem getting Add-ins to show up in VS2005.

I created a simple add-in using the MSDN Walkthrough: Debugging an Add-in
Project document, but no menu items ever show up in Tools menu, and no items
ever display in the Add-in Manager dialog.

I know the Add-in's XML file is being used because if I edit the file and
make the contents invalid XML, I receive an error from Visual Studio telling
me the file is invalid.  When the file is valid, I see no errors of any kind.

I've tried changing the values for the LoadBehavior and CommandPreLoad tags,
as well as the /resetaddin switch on the command line without luck.  I even
tried the /log switch on devenv but saw nothing useful.

I've also tried installing other Addins like GhostDoc, but these also fail
to work/register and I see nothing in the Add-in Manager dialog.

Is there a security setting that could be keeping the add-ins from loading?  
Can anyone suggest a method to help me debug this problem?  In case it
matters, I also have Visual Studio .Net 2003 and Visual Interdev installed on
the same box.

Any help would be greatly appreciated.