Well ... i am on turn 114 and it has happened only approx 4 or 5 times. I have not been able to reproduce it on command. Sequence always the same :
esc> save game> (to an existing file with double click) > back to game .
EDIT - Now duplicated
When i save to an existing file with double click DEPENDING on which file i clicked on (6th file top), when the options screen come back up the pointer can be directly over the AA box left arrow . when this happens the AA selection changes even though it was not clicked on. If i move to say the 5th or 7th file everything is ok