Sculpt tools wok on a UV sphere, but not on my model I am making.

The sculpt tools work fine on a UV sphere, but when I try to sculpt my model most of them do not work on it . Mainly the crease tool for wrnkles in the face; could I have done something to the model to cause this? I mean some of the tools go to exstreems and move a lot of the pixels but not the way they are suppose to. I downloaded a tutorial that someone give me a link to and watched it 2 times but did not catch anything that could be causing this. Please help me if you know what is happening.

Dum (a) Boobers