To facilitate efficient navigation within the tree list of every screen in the XL, there is a timer that is used to delay when the right hand side of the screen is populated based on the current tree list selection. The timer is reset on every key stroke until the user pauses key strokes long enough for the timer to expire and then the right hand window is populated. If this timer did not exist, a user would have to wait a noticable amount of time for the right hand window to populate, in between each keystroke.

This timer, combined with the addition of "Are you Sure?" windows and other window prompts, opened the door for race conditions where code for an object is running with pointers on the stack that can then be deleted during the window prompts execution.

This was resolved by testing to see if the main widow has focus before acting on the timer expiration. If the window does not have focus, a flag is set that will refresh the window once it does.