The Lions have won just one of their last seven matches in what has been a tough end to the season following the disappointment, on and off the pitch, of their FA Cup semi-final defeat by Wigan.
Manager Kenny Jackett admitted: "It was a poor goal to give away from a set-piece.
"We had plenty of time to get back into it and I can't fault the commitment of the players but we needed a break, something to fall for us.
"Ultimately it's disappointing as you need to score goals at home and creatively we weren't quite there in this one.
"We've been close but not close enough, which has been the story of the second half of our season."