I have this strange leak in my townhouse roof. Visible leak that happens when
there is heavy rain and wind.

I've had 3 people look at it. Each of them say that my flashing is ok. the
problem may be with my neighbor's roof siding. Rain water gets behind the gaps
between them and leaks into my roof. I have a stain in my ceiling.

Has anyone seen this type of problem? What is the solution, other than fixing
loose siding?