No, there is no MDI form. I actually found out why this phenomena is happening. Apparently, by design, a form with menus has to have a visible border. My solution was to create a separate form with just the menus needed for right-clicking. Every form that uses the same functionality for right-clicking references the new 'menu' form. The solution worked out quite well, actually. The problem is referenced (as I found out later) in the MS Knowledge Base under Q174214.
Thanks for taking the time to respond. -Deanna.