The "all of a sudden" I mentioned really meant "the first time I used N1MM+ in a contest where I called CQ, the problem happened..."!
I loaded the latest 2.85 beta and it seems to have fixed the problem - if I am calling CQ and K4RUM calls me, I can type in K4RU hit enter. N1MM will start to send and I can enter the last letter M and N1MM+ will send K4RUM - all is good.
I tested it out a bit last night in the CWT test it worked fine, but I was able to cause one bad crash. Not quite sure, I couldn't seem to repeat it, but it crashed N1MM and trashed my Com Ports, had to restart PC.
I *think* the actions that caused the crash: I called CQ (hitting F1), W3ABC answers. I start typing W3AB and then hit SPACEBAR by mistake, which advances cursor to next entry box (in this case that is the NAME field). Hitting SPACEBAR doesn't not initiate response, so I hit ENTER key - kerplooey. The ability to keep entering a callsign while CW is being sent I think should only happen after the ENTER key or LOG command is given - the cursor is still in the callsign entry box. If the cursor has been advanced, should not be going back to callsign buffer unless cursor was moved back there.
I dunno if that makes sense - tonight will try it again in the NS Sprint and see what happens.
Thanks for all the updates on this.
73 John K3TN