new annoying behavior

This has actually been happening to me for a while (no, I don't really  
remember when it started) but it's finally annoying enough to ask about  
it.

I hit "Check" and most of my mail sources get checked quickly.   
However, one of them has invalid credentials, so it sit's there waiting  
until it times out after about 30 seconds.  Nothing unexpected there.

The problem is if I hit "Reply" on some message in the inbox, before  
that timeout.  I start writing my reply, but as soon as the mailbox  
read times out, I get a popup with the error about not being able to  
connect to that mailbox, and the main window pops back to the forefront  
- and invariably my typing triggers several unwanted actions based on  
what shortcut keystrokes happen to be part of what I'm typing into my  
reply.

I wouldn't think there would be any reason to change any window  
positions or focus just because the "Check window" dialog finishes and  
goes away, but it looks like it's automatically (but is it  
intentional?) putting focus back on the main window.

Is this intentional?  An unintended consequence of some other  
intentional action?  Is there anything I can do other than pay more  
attention?

As always, thanks for any suggestions.

Jack