new problem with Balsa (git head)

I'm not sure exactly when this started - but I started noticing it a  
few weeks ago.  Initially, I only noticed it when running balsa  
remotely (ssh -Y) but have now confirmed it also happens running  
locally.

Every now and then, apparently when I select a new message (not unread  
- just switching messages to one which has not been open recently)  
Balsa simply stops responding for somewhere around 45 seconds.  It  
might even be the first message displayed when switching to a different  
mailbox.  I can move or resize the window, but that is being done by  
the window manager, and there is no redraw until Balsa returns from  
wherever it went.  I see nothing that looks remotely relevant, even  
with command line debugging turned on.

My vague suspicion is that it might be related to Balsa trying to check  
something about a PGP signed message, and making that check  
synchronously instead of asynchronously.  Pure suspicion with no solid  
evidence, but at least every message I have noticed that has caused  
this has been signed.  I'm getting no errors regarding the signing,  
however.

I only see one large patch applied after the parallel POP3 fetch  
changes, and I'm pretty sure the POP3 changes were not the cause, but  
none of the changes in the other patch strike me as suspect.  Note that  
these problems are not happening when fetching new mail, and can happen  
when displaying messages retrieved months ago, not necessarily recently.

Any thoughts or suggestions on further troubleshooting?

Jack