Here's what happened.  Was transferring another area of the board by using the number keys to move a stack but leave 2 behind each time.

Then I went to move the 18 from where it is shown in the picture.  Since I was just using the number keys I tried to move them all by typing 17.  The player then showed 2 and 17 so I assumed it had just picked up the 1.  So I moved the 1 back, and when I tried to transfer 15 with the dropdown list I got the picture shown above.

When I refreshed the player it showed 6 and 13.  Which *almost* makes sense, but I would have guessed it to show 7 and 12.  Anyway... there ya go.

Ok that is pretty confusing... will go through the logs to see what happened.

The number hotkeys only work for numbers 0-9, so I would expect it to transfer 1 when you typed in 17.