Hi Peter,
thank you very much for your answer.
The short term solution became quite obvious after unpacking the gasket.
There is a self adhesive strip on the gasket.
I assume that the combination of very warm weather, lots of salt and sand here in Muscat will make the gluestrip on the gasket fail pretty soon.
When I am in Europe next time I'll get a tin of hypabond-contact-adhesive.
Cheers,
Dirk