Update: SA 126.96.36.199 (latest update) now appears to be working successfully with Yahoo mail (ie, I am able to drag-drop email, and drag-resize reading pane).
I had occasion to do several System Restarts, and today I see that the SA problem is not present with Yahoo mail. As far as I can tell, there was no further update of SA (the About shows 188.8.131.52, the latest update), but the problem is not present at the moment.
That is good! I will post here again in the event the issue returns, but hopefully things have been resolved. Thanks for your help.
Message was edited by: billseymour on 1/26/11 11:45:47 AM GMT-05:00