No Queenside Castling?

Are you putting the king on the right square, two squares towards the queenside (not the square next to the rook like when you castle kingside).

I'm in the middle of a game and cannot castle queenside.   I have not moved either piece, the Knight and Bishop are clear and I am not moving into check.  I noticed this on one previous game, but decided to make another move.  Now it looks like this is my best move and I will probably time out rather than make another move.

In your game, the d8 square is covered by the White Bishop. Your king will be moving through check if it castles, which makes it an illegal move.

Your answer is here (paragraph 3.8):

http://www.fide.com/component/handbook/?id=124&view=article

5 rules of casting. You cannot castle into, out of, or through check. Nor if piece in the way or if king or rook moved.

For the record I have played chess for over 50 years and know the rules blindfolded. I love Chess.com but gave up when it would not let me queenside castle legally.   I simply now play on a (real)  board and text my moves to my partner.

Care to post a link to the game in question.

Chess.com handles castling both sides perfectly well.