Good to hear that you ruled out the culprit.
Steve, did you actually load a venue, or are you still seeing the default opening screen?
If this isn't the reason - do you see the Venue Map (i.e. the floor-plan), or is the main window empty? In this case, there might still be an issue with the graphic settings and/or features of your system.
Apart form that: Clicking the "HotSpots"-button below the lower the main window's lower right corner will give you an idea where the valid spots are. An Icon moved to the outside of these areas will bounce back, or - if you changed the Venue within an existing project - will be greyed-out and muted. Just zoom out as far as you need to see them again, and move them to the valid area.
HTH,