How to create solution add-ins in Visual Studion 2008 - add-in

Question

I'am trying to create Solution Add-in with the help of this link:
http://msdn.microsoft.com/en-gb/library/vstudio/ms165621(v=vs.80)
However, I've been loosing. I follow those instructions carefully, but I think that something important is missing from my view. So, this is the order of what I am doing, and what I am planning to get:
Create default Add-in solution with the help of Add-in wizard. Since it is planning to be a solution add-in, I remove the XML declaration file.
Check "register is as a COM object" in the properties tab.
Use regasm to register the add-in as a com object in the windows registry.
And this is where the troubles begin. As I understand, I must write the following code from the link into my OnConnect event of Add-in class file. Ok, I've done that. Build project, and everything is fine.
BUT I don't understand how to associate this add-in with solution. MSDN says:
"When Visual Studio loads a solution, it first examines the solution (.sln) file to see if it references add-ins. If so, it loads them and calls the same IDTExtensibility2 methods as a regular Visual Studio add-in."
When I'am trying to debug add-in, I've open my external solution, but nothing fires in my OnConnect event, untill I've checked the add-in in Add-in manager window.
Is it intended to be so, or I am missing something important in this steps. As I understand from descriptions, solution's add-in OnConnect must be fired at the moment, when IDE opens any solution file.

Answer 1

I understand that this won't help you much now, but might help someone else. I have faced the same problem last week, trying to make add-in that will load and be active only with one solution. Ended up on the same MSDN page and stuck on the same point :).
To make solution add-in follow the link provided in the question. Follow all the points listed except point number five - skip adding following line of code in your add-in logic:
EnvDTE.AddIn addin = _applicationObject.Solution.AddIns.Add("MyAddin.Connect", "MyAddinName", "My add-in description", true);
Open text editor and edit .sln. Input these lines at the end of .sln file in the global section:
Global
(...)
GlobalSection(ExtensibilityAddIns) = postSolution
MyAddin.Connect = 1;My add-in description;MyAddinName
EndGlobalSection
EndGlobal
This is exactly what _applicationObject.Solution.AddIns.Add() inputs in .sln file
Now when this solution is loaded into visual studio, while loading solution it will also load this add-in. One more thing to add here:
when add-in is loaded this way, connectMode param passed to the OnConnection function has value ext_ConnectMode.ext_cm_Solution.
Hope it helps :)