bouncybouncy:  It's certainly not cheating if both players are aware of the time limits and agree to them.  Since extremely short time limits are not "normal" on this server, I think it is good practice to call the opponent's attention to them, perhaps in the title of the game.  Otherwise, a person could accept a game inadvertently under circumstances where they would have to time out, presumably spoiling the game for both sides.  After all, we don't play games primarily to win them, but to enjoy the company and competition. 

Whether it's "cheating" to set up games without a warning is a matter of opinion.  I think it's unfair if it operates as a trap for the unwary.