Dear Mike (and also Alex & Reinhard, as I'm not sure how large your part in this is/was, and I don't want to see you go uncredited if you were involved):
THANK YOU THANKY YOU THANK YOU!
This bug has been a royal pain in the *ahem* for months and was a large part (the others being NX4 going closed-source, and the inferior sound support) of what drove me away from NX (where nobody seemed to be willing/able to fix it) to X2Go.
Glad to see its presence in the X2Go code was very limited in time.
Kind Regards, Stefan