I've been having the same problem of my high scores not registering. I've been playing the expansion levels a lot lately, and at least half of the time the high scores don't register on OpenFeint. The scores also don't show up locally, i.e. the scores shown at the level select page are not the highest ones I've achieved. I have also experienced the same thing that SuberB has, where the game says I have gotten a new high score, when the score is less than my previous high.

I have to say that one of the fun parts of geodefense swarm is competing against all the other players in the world to see how I stack up against them. It is very disappointing to work for a high score, only to have the game fail to register it anywhere. I was very pleased to see that you had created new levels, but I can't really recommend them to anyone until this high score problem is fixed. If you want me to post them, I have screen shots of my scores and of them not showing up on Open Feint.