resizing a TControlBar - Width property

Hi all,

I don't know why TControlBar Width seems to
have a different pixel resolution than all other
pixels dimension properties. I have looked in
the help and tried to find out but didn't find

I created an ActiveX in Delphi (Active Form) which
contains a TControlBar then I added a new property
for resizing the internal TControlBar from the control
container, that means changing the TControlBar.Width
but the problem is that the pixels in the TControlBar Width
seems to have a resolution of approx 13.005 more width than
all others like VB Form.Width or Delphi ActiveForm.Width... can
anyone help and explain why this? Is it that the Width property
of TControlBar is referering to something else in this case?

Thanks in advance and regards,