model space within a viewport not functional

I'm in paper space and I've dbl. clicked in a viewport and the edges of the viewport have highlighted, but when I pan or zoom within the viewport the entire paper, drawing and titleblock move, as if I were still in paper space within the viewport. How do I get model space to function within my viewport?

The viewport is locked.

DNK, I rt. clicked on the viewport and where it said Display Locked, No was checked, however, when I rolled over the viewport, I noticed what appeared to be a second viewport. Deleted it and things seem to work again. Must have created a second in my CAD excitement.