ItemEnabled Doesn't paint alright in Checklistbox

When I falsify the property ItemEnabled [ index] of an item in a
tchecklistbox in delphi 5, the checkbox is grayed out, but the item is
still active. I set the property from the formactivate, in which I also
load the listbox with items. The strange thing is that when I scroll over
the item in the listbox, when it isn't the selected item anymore, the item
is grayed out entirely, so before only the checkbox was grayed out, but
when you step over it, the item also grayes out as it should have
initially. How can I make sure the item is drawn properly without having to
step over it to display it right ?

Thanks anyone with help.

Mario Verschuur