I had several problems in game #3388226 on oregon relating to the undo button.
First of all, at about halfway through the game, my opponent requested an undo. I accepted, but nothing happened. So, he tried again. Then it triggered, but the game went back in time about 3 turns.
Later in the game, I requested an undo. He accepted, but nothing happened. Then the game froze. I resigned then and even the post-game report was messed up. He had over 90 points and the game had lasted like 20 or 30 turns, but the post game report showed the game ending at turn 12. Other than the undo problems I didn't notice any connection issues, so it was weird.
I'm using chrome browser on Mac OSX.