While renovating a bath room, we added a bathtub/shower. After completion we noticed that some water does not drain. It collects in the middle of the tub. It's not a lot of water, but still should not be there. The contractor says that the tub was not molded properly. Not sure if I believe him since we had some other problems. Of course the wallls are all in and finished now, so my question is whther there is anything I can do about this. If I have to go into the wall and try to shim under this area I will, but is there any other suggestions.