I just discovered this.

I was playing the new Happy Feet Sink Or Swim game, the only rules are to eat fish, and not hit an iceberg, because then you die.
So I played, and I kept dying even though I didnt hit any icebergs, and I saw no timer, so I was like what's going on here? I couldnt score over 300.

I played the same game on the official happy feet site, had no problems, and got a score of over 600.

So it seems Neopets shortens their sponser games, which in turn doesnt allow us to get that many NP's from them. I personally felt like they cheated me and let it be known on the boards, but then again sponser games come and go very quickly.