Something odd happening with Dig Dug for me - I got a score registered earlier, (17440 iirc), then later on I played and got a lower score, but it didn't show up in the 'recent activity' log. Then I played another round, and got a score of 19980 which would normally replace my score (2nd place below Jumpman) but it didn't - and it didn't show up in the recent activity log either.
Funny thing is, all my scores show up in the high score table in the game itself whenever it's played (ie all my previous scores are saved, including the ones that didn't register in c4a), so I'm wondering if in order to register another score I might need to delete the game's high score file...
Jumpman, have you played another game and noticed similar?