No Dropdown Arrow on Toolbar buttons

I recently installed an application on a Windows 95 PC. I have 3 buttons in
a toolbar
that have their style set to tbsDropDown, but when I run the application the
arrows do not appear next to the buttons.

The PC has IE4 installed and the dropdown arrows appear next to its toolbar
buttons as expected.

Can anyone please advise what I need to do (in the installation routine for
my application) to make certain that the dropdown arrows appear on the
toolbar buttons?