Thanks Guys, for all your helpful comments and suggestions; it's certainly reassuring to know that it's not just me. But I'm still intrigued to know why the M3W seems to trigger the issue more than other vehicles and, as others have said, there is also the volume multiplication factor.. I too have had prostate cancer which clearly doesn't help, but I'll switch to decaff and may well give the 'in-flight plumbing' a try; Thanks for the link Auster.
