As always, thanks for the prompt and comprehensive response. I'm still struggling, but I'm now starting to suspect something odd going on with the VS install itself. Either that or I am about to demonstrate my complete ignorance of how extensions
>> You could try uninstalling it using the Extension Manager in Visual Studio
Tools / Add-in Manager .... only shows Ghost Doc
Tools / Extensions and Updates .... lists several installed extensions, but not SHFB.
>> then running the .vsix installer directly
This was interesting. I found SHFBVisualStudioPackage_1940.vsix but it doesn't have an application associated with it. Should it? I tried copying that file to two profile locations (Local and Roaming) under the VS11/Extensions folder.
Restarting Visual Studio did not pick these up.
>> try creating a new solution with a blank documentation project from scratch
The new project dialogue box doesn't offer a Documentation Project as an option. That seems to add weight to VS2012 simply not knowing about the VSIX in any way, shape or form.
Not sure where to go from here. Maybe it's a matter of using VS2010 for the documentation project until VS2012 RTM appears, and then looking again?
Thanks again for all the help.