Calc key (keycode 183) on keyboard problem

Users of my app have a keyboards which have a shortcut key for a calculator.
My application is an MDI frame written in C6.2 ABC.
After starting any window (with the MDI child property) using:
Start (Myexample_brw,25000), the keyboard shortcut for the calculator does not work.
When the MDI Child property for Myexample_brw is disabled, the calculator boots up.
Any ideas, how to solve this problem?