set backgroundcolor for CXTPControlStatic

Hi there,
how do I set the background color of a control (in this case CXTPControlStatic) ?
I am using CXTPControlPopupUndo with a listbox for the undosteps and an label (which is the CXTPControlStatic) to show information.
I want the label to be separated from the listbox with an horizontal line and the color to be different from the one of the listbox.
Using the VisualStudio2008 Theme that works fine but with other themes it does not. How can I set color/separator? I tried using: "pControlListBoxInfo->SetBeginGroup(TRUE);" which does work for the VS2008 Theme but not for some of the others...
Thanx for some help.
Cheers Björn

Hi,
thanx for your advice.
Unfortunately that did not change anything.
This is what I do so far:

CXTPControlLabel *pControlListBoxInfo = (CXTPControlLabel*)pUndoBar->GetControls()->Add(new CXTPControlLabel(), UNDO_INFO);
pControlListBoxInfo->SetBeginGroup(TRUE);

...(and later I set the text to be displayed on the label)...

How can I set the background color for pControlListBoxInfo ?

Thanx for your help.
Cheers B

As I found out now, the following was the case:

when using: "XTPSkinManager()->LoadSkin(SkinFileName, SkinColorInfo);"
to not set or set the Skin&Color of the app to values that don't exsist

or

using a "xtpPaneThemeNativeWinXP"-Theme on a Vista machine the described behavior happens.
When setting Theme, Skin and/or Color to valid values everything is fine...

Thank you very much for your help and your time!
It is always good to know that there is someone out there :-)

Cheers B