mesh issue
 

Can anyone tell me whats happening with the mesh in this picture? Why does their appear to be small discontinuities here and there (lines crossing cells, etc.).

http://img8.imageshack.us/img8/4571/meshissue.jpg

You are using a trimmed mesh. Those lines are the faces of the cells. Not all cells are cubes. The cells that have the lines have two triangular faces instead of one square one.
This is not a problem and it is part of this mesh type