When I tried to use the Nudge tool, it pinches the photo instead of actually nudging it. This is what it does to the photo:
Any reason what could be causing this issue? Is this a glitch in Zbrush? I need to nudge the photo to fit my 3d model. And all the Nudge tool does is sink part of the photo. I tried adjusting the brush size, messing around with the brush intensity, switching brushes, nothing works. 
Also, why does the Nudge freezes Zbrush all the time? Please help.