Thanks Skycastle, the eye thing was what I was after...that does the job of hiding the image plane...
Unfortunately, even if i reduced the visibility to zero, I'd still get an annoying grey box where the Image Plane should be...not sure if that is a software bug or my video card (FireGL 5200)...
I'm somewhat befuddled as to why mudbox does not allow you to completely remove an image palne after one has been assigned....would seem that after you've assigned an image plane to a camera, you can only toggle its visibility or change it to a different image?
thanks again!