Having a weird problem that looks like a bug, though have found a workaround that working so far:
Using Baseball league with 2 point rule, automatically doing team rankings. I enter results from first 5 games and click "Update Results". The first place team indicated a games back of -0.5, the 3 teams tied for 2nd had games back of 0 and the 5th place team had games back of 0.5. The correct standings should have been 0 for first, 0.5 for 2nd, and 1.0 for the last place team. (note: it is impossible to be negative games back).
Anyway, what I found was that if I then go back and click "Update Results" a second time (without changing anything), the Games Back was then calculated correctly. This is consistent and repeatable.
Hope this saves others hours of head scratching (until it's fixed)