You are correct Mike, GT and this site are the only ones with this bug. I have played at a lot of the online sites over the years and have never struck it before, and it is a basic rule, as is the rule there should never be a draw in the game of backgammon. It can give a player a huge advantage to NOT have to play the higher dice.
And Kevin as for notifying Fencer everytime it happens so it can be fixed manually, well that sounds terribly time consuming to me, wouldn't it be far easier just to fix it so all of the gammons are coded correctly. I have seen this fault in backgammon, nackgammon and backgammon race here, so I guess it is in the other 2 variants as well.
And I am going to mention the rating system again, the BKR is unsuitable for the gammons, it is the same rating system which was originally used at Goldtoken and is really does not give a good indication of player strength.