En Passant not possible?

As far as I can tell, in this game, an en-passant would be possible right now.

http://www.redhotpawn.com/core/playchess.php?gameid=4577966

Why am I unable to do this? Is there some extra rule to en-passant I am unaware of?

My en-passant would threaten the white queen, and put white in check. I'm thinking maybe en-passant cannot be used if it puts your opponent in check, but I cannot see that rule anywhere...

Certainly, Wiwkipedia doesn't cover that...
http://en.wikipedia.org/wiki/En_passant

Game 4577966

Taking the pawn en passant (d4xc3 ep) would leave black's king (d8) in check by white's queen (d2).

Any move which leaves the moving side in check is illegal.

If that was not the case, you could have taken the pawn en passant.

nm - I'm an idiot.
It also puts me in check, which is why it's not allowed...

Thanks LekZ - you saw that just before I did...

Originally posted by Jamdog
Thanks LekZ - you saw that just before I did...