Toolbar paints separator for invisible controls?

Hi all,

I'm using some controls (other than toolbuttons) on a TToolBar (Flat mode)
If if hide such a control by assigning Visible := False, the toolbar still
displays the space occupied by the control
and a spearator in the center of this space. I had a llok at the source and
it seems that for each non toolbar control
a substitute toolbutton control is inserted to encapsulate the control.
I tried to access the ToolBar's Buttons[I] property and set each button to
auto size,
but that causes AV's without further effect.

Is there a way of hiding this encapsulating button or forcing it not to
paint the separator? (I'd rather not set the encapsulated control width to

Thanks in advance,

Gerrit Beuze