Rovers struggled in the first half as the league leaders imposed themselves, Mark Hudson's 30th minute header giving the visitors the lead.
Joshua King levelled minutes after the restart but Cardiff responded immediately through former Rover Craig Bellamy, but had Mauro Formica not found the crossbar instead of the back of the net moments later the match could have gone either way, but two goals in two minutes from Cardiff consigned Rovers to their third consecutive home defeat.
"This is a results business and we are not getting the results at the moment," the boss told Radio Rovers.
"We are disappointed with that, I'm not here to sugar coat anything, we didn't defend as well as we should have done on all four occasions.
"It is not like it was fantastic play by Cardiff, they were strong, they were solid and they did what they needed to do and their finishing was better than ours.
"It doesn't matter if you have more shots on target, the most important thing is to score goals.
"Maybe it is a lack of confidence with the two losses against Millwall and Bolton. I had hoped that the draw at Burnley would help but today we were not as sharp, not as good on the ball as we would like to.
"We just have to make sure that in the next game that we have the quality and the courage to play and to pass the ball as we are capable of as we didn't do that today."