Quote - An Area Render cursor that is not the same as the default Arrow. When trying to pick up to the edge of the frame, I keep undocking the preview window instead of selecting the render area. Thanks.

Whichway

 
Vaild suggestion, but in the meantime have you tried unselecting Drag-Docking Enabled.. for your Preview window..?

"You don't have to be mad to use Poser... but it helps"