ZBrushCentral

Image Grid and snap to mesh problems

Here is the problem I have, upon start up under Lightbox you have a number of options one is Grids. With Grids selected you see a skull image plane grid you can use to build a skull. I started a project and got a good way along on it but now it is giving me fits. I will load my tool and the grid skull image in lightbox then with the first tool under SubTool selected ( my main piece) I go under Draw>Snap>Snap to Mesh. Every time I do this I need to readjust the size and position to start work. Now even when I Activate Symmetry now even that is off. Any ideas? I hope this post is in the right spot for help. I will even post the file.