We have an error where we randomly have a screen disappear (apparently from memory). Has anyone else seen this behavior?

Process:
We call the screen, select a record on the screen and click on the screen. It vanishes. If we try to call the screen again from the menu, it gives us an Object not found error, meaning the reference to this object disappeared. 90% of the time, this does not happen. It happens more frequently on Pentium Pro machines. It can be duplicated on any machine by starting about 10 copies of the program first and leaving them open while running the 11th copy.

Background: We have an application that uses a framework that we modelled on the framework that was used in the revolutionary guide to VFP. While we are running the program, we randomly get XXXX is not an object, where XXXX is the same object every time. It is also an object high up in the hierarchy of our framework.