Question about tokens

[Kashmir6449]

Could someone enlighten me as to why this happens? :  I've noticed that on several games on Pogo, if you get back to back large token scores, it doesn't give you full credit for the tokens actually won.  Word Whomp Whackdown, Pop Fu, Turbo 21 are just a few of the games that I've seen this happen with.  I know the question has been asked before, and I remember seeing people's answer as it has "something to do with Pogo's rollback" or something like that.  What exactly does that mean?  Can someone explain that a little better?

An example of what I mean.  Playing WWW, I get all words right and the speed round.  So let's say I have a total of 450 for that game.  The first time, it gives me credit for all of the tokens.  Next game, I complete all the words again, and this time I get a score of say 460.  From this point on, it only gives me credit for say 220 tokens or so.

Any help in clarifying this problem would be greatly appreciated!