knife tool issues, b mesh, etc..

Hi. I’m new to the forum. Having some issues with the knife tool. I’ve got a human body model where I began by box modeling, subsurfed and sculpted.but I am h as having trouble getting the knife to cut what needs to get cut. Sometimes even with the solid surface selection (non X-ray )selected t e knife might cut some backSide, some front, create verts with no edge or just not work. Do I need to somehow activate the b mesh mode? Or what?

Bmesh is included in Blender 2.63 and later.
Knife tool has had issues but it’s much more stable now in latest versions of Blender.

Check that you don’t have double geometry. K is shortcut for knife tool, shift+K is shortcut for knife that cuts only selected parts. Also check the 3D view header for options when using the knife tool, those help in defining the cut(s).