Wrong Antes/Blinds

[K-Lo]

Curious to get opinions here:

You are called to the table, the blinds have just gone up: 500/1000, 100 ante.  You catch up with the action just before the flop is dealt, 4 callers including the bilnds, there were no raises.  The dealer indicates that the clock was misread, and everyone anted 200 instead of 100.  

a) Would you refund the 'extra' antes to the players?
b) Would your answer be different if the error was caught after only two players had folded pre-flop?

[Nick C]

Very interesting, Ken. I would have no problem reducing to the correct amount before 2 players have acted. However, I would also have to insist the incorrect amount remain after 2 players have acted. In this case I would have no problem explaining substantial action as my reason.