Ultimate Bet Bonuses and withdrawing

[zjo1981]

I apologize if this information is already out there, but I suck at the search feature so far.

I have the Ultimate Bet 111% bonus right now. I was wondering about cashouts. Particularly this statement from UB's site:
"Players that deposit and withdraw Real Money without significant amount of play will be required to forfeit their bonus dollars.. "

Anyone know what a "significant amount of play" is exactly?

Any help is appreciated.