Debug not working? (C# express 2010 + Rhino 5.1.20620 - 6/20)

The breakpoints are not working. 

When I start the Debug, Rhino is launched. As usual I launch Grasshopper (COFF is turned off). I can find my component and use it, but the breakpoints are not working!

Any suggestion?

Thank you

Serge

(Rk. I'm using the wizard to create the plugin)