Shortcut Keys Behaving Strangely

A SSTab control has 5 tabs. It houses many controls due to which the shortcut key for more than 1 control is the same.

The SSTab has a CheckBox & a CommandButton which reside in 2 different tabs. The shortcut key for the CheckBox is Alt+Z & that for the CommandButton is Alt+C. Alt+C happens to be the shortcut key for 5 controls but Alt+Z is the shortcut key for only the CheckBox.

When I press Alt+Z on the keyboard, strangely the focus alternates between the CheckBox & the CommandButton though Alt+Z is the shortcut key for only the CheckBox.

Pressing Alt+C correctly alternates between the 5 controls including the CommandButton which I have referred to the earlier para....that's OK but why is Alt+Z alternating between the CheckBox & the CommandButton though Alt+Z is the shortcut key for only the CheckBox?

Please note that I have assigned all the shortcut keys in the Properties dialog at design time.

First of all I think that having the same shortcut for more than one control is not a good idea. They are meant to be unique so that a user can "click" a specific control. If you want the user to be able to go from one control to another the normal way is via the Tab key. In any case your problem sounds to be like there is something in the code that is causing your problem. If you want to see if any code executes after pressing Alt+Z you can use my Insert Procedure Names Add-In.