Ladder Challenge Bug?

I play in the 3 day chess ladder.

I beat Sleepyguy in this ladder on 22nd Dec 2009. Today it is 6th Feb 2010, about 6 weeks since that game finished and Sleepyguy has moved above me in the ladder , happily he is within within challenge range. We have both played a couple of other ladder games since, However when I try to challenge him I get the message "You cannot challenge this player within 14 days of your last game".

Is this a bug, should I be able to challenge him or am I falling foul of some other rule and the message is just wrong?