normaly in maya when you have imageplane in all views , in front view-topview-sideview the image plane should be behind the grid not in the infront of grid only in perspective view is different, but with my maya i see the imageplane in top-side-front view infront of the grid. I have never ever ( to my knowledge ) been able to move or seen anyone move a image plain behind the grid display in Top, Front, and Side views. Even the online tuts and books that I have read have never shown that kind of a feature. The Top, Side, and Front views were never designed to work in 3 dimentions like the perspective does, they are 2D. Thats why the grid cannot move infront of your image plain. in those 3 views. The only thing you can do that comes close to what you want is to reduce the opacity ( via alpha gain ) on your image plains. If there is anyone has been able to do this, please drop by and explain how to do it.