Add-in does not load

Hi !

I have created a C# Add-in under Visual Studio 2005 Pro with VSTO 2005 SE.
I use Excel 2007/Win XP Pro.

Under Visual Studio 2005 debugger (where Excel is lauched as an external
program), the add-in works fine. After at least one debugging session, the
Add-in works fine too when I launch Excel direcly (I mean not under Visual
Studio control).

Then, as soon as I deinstall (add/rem programs) the add-in and reinstall it,
the add-in is not loaded anymore in Excel (I see in Excel/Excel
options/Add-ins/COM Add-ins: "Not loaded. A runtime error occured during the
loading of the COM Add-in).
Again, if I launch a debugging session, this problem disappears.

I have included the following prerequisites in my VS 2005 setup project:
* .NET Framework 2.0
* Shared Add-in Support update for Microsoft .NET Framework 2.0 (KB908002)
.... not sure if I really need it (BTW, behavior is identical if I remove it)

Any idea is welcomed. Many thanks in advance.

Cheers,

Pierre