Let me repeat: the Deepbit hashmeter is useless. It does not reflect anything useful. I've had it say I'm doing 500 mhash consistently for about an hour, and I do around 300.
I call it "the luck meter" for a reason.
It may not reflect your real hashing speed correctly, but your reward will be the same as if you were hashing with that displayed speed and "normal" luck.
So if you saw 500 MH/s on the luck meter, then you were 200 MH/s more lucky and got 66% more BTCs.