Ok. I found the bug. The sessions on the server were timing out too quickly. So if you played a game for more than roughly 8 minutes your session would be gone. This has been pushed to 8 hours. I doubt anyone will play a game for that long.
The good news is that I was able to enter the game scores that were lost, so there were a couple of high scores included in those:
nukbucko
Space Invaders
Score 77020 (Sorry Jackal, I saw your 32220, but nuck had you beat)
nukbucko
Hexxagon
Score 36
The other scores were entered in the player's record. At some point soon you'll have access to view your playing records.
Thanks for the feedback and let me know if you find any other bugs!
-Paul