Event procedures that are triggered recursively can cause application errors, for example processing a grid control while holding the Page Down key. If a control's event procedure is long running, it can fire a second time before the processing of the initial event procedure is completed, resulting in the procedure being recursively. This could modify variables that were in use when the procedure drops back to the original event's processing.
Set this configuration variable to 1 (True), to ignore events until processing returns from the control's event procedure. This is useful for applications that encounter difficulty processing events. The default value of this variable is FALSE.