If you look at my programmers profile BlackJack, you can see:
flag weight 518.3176
I'm pretty sure that's not supposed to happen..
After 500, your flag weight increases asymptotically towards the current cap of 750. Because of this, as you get closer and closer to the cap, it's possible to only receive .001 flag weight.
So rather than display a rounded number (and thus, no change as you get closer to the cap when you flag correctly), it's shown as a double once you pass 500.