Problems with menu in Builder C++ 6

[Wojtek]

Hello,

in one of windows of my programs the main menu of that window
does not work properly:
- submenu items don't show get visible when chosing main menu items
- main menu items only get lighted when one puts a mouse cursor over them,
but clicks don't fire onClick methods.

In other windows menus works OK, only in this one there are problems.y.

Have anyone seen such strange behaviour? What can be the source of the
problem?

Best regards,
Wojtek