The other day a customer of MZ-Tools 7.0 reported an exception in the Sort Code Elements feature that after investigation turned out to be a bug of the file code model.
I have documented it here:
BUG: EnvDTE.CodeElement.StartPoint.Line wrong result with duplicated ‘using’ statement.
And I have reported it to Microsoft Connect:
EnvDTE.CodeElement wrong start line for duplicated “using” statement