There is no clear reason why this is happening because it shouldnt unless you accept it.  

All i suggest is write to 

support

 and they might be able to help you.

Toothpaste,

This happens all the time and the ppl that operate this website know it. I just had the same thing happen to me. My opponant "Frank2000" had even disconnected three times hoping it would throw the game in his favor, when it didn't he kept offering a draw until the server accepted it.

Surely this isnt right?  If this is continuosly happening the matter needs to be looked at.  Surely the draw can only be agreed if 

both

 players agree on it? :S

Same thing - opponent kept clicking I kept refusing then stalemate and loss of points - FOD - FIX IT!