Client size of TTabControl WRONG

i was hoping someone can confirm a bug i found, and perhaps propose a
solution.  Create a TTabControl on some form.  now, put some other
component such as a panel on the tabcontrol.  Try to size the panel to
the height of the client region of the TabControl without using align.
i use ClientHeight, etc... these are the same values as Height, etc.
it's writing over my tabs.  why?  anyone know the real solution or a
workaround if it's a bug?