Thank you for your reply.
My choice of words in my previous posts may not have completely and unambiguously described my system or my concern with how Pegasus Mail 4.6.1 behaves. I apologize for any confusion that I may have inadvertently caused.
First, to be clear, my memory is good. God willing, it will remain so for many years to come. I can remember which browser is my default browser. Pegasus Mail does not need to remind me.
Now, as I stated before, I'd like PM to always behave as if *it* remembers which browser I selected as default. Asking me to choose from a list of available browsers every time I want to "Open message in Web browser..." is inefficient. So is double-clicking on a menu entry when a single click should suffice. PM4.6.1 is asking me to do more work than is necessary for a routine task. Not much more, but more nonetheless.
This behavior is very much like a waiter at a restaurant asking me to read the menu again and choose my entree again before delivering it to my table. I have already told the waiter my choice. It is the waiter's job to remember my choice. I think it should be Pegasus' job to remember my default browser and employ it where ever it is appropriate to do so.
Thank you again for your attention to this matter.