My bathroom sink is leaking through the little thingy at the top of the trap. I have found an image of it (see link below). I took the rubber flap out of this and cleaned it but this has not solved the problem. Can anyone offer any advice on how to rectify this problem? I would be deeply greatful!
http://img147.imageshack.us/img147/1192/mcalpine32mmantisyphont.jpg
http://img147.imageshack.us/img147/1192/mcalpine32mmantisyphont.jpg