Host Container for DockManager

I am a newbie to VB .NET and even newer to the UIStudio Dock control. I have searched through (most) of the topics in this forum, but did not find this question. I am just trying to get familiar with the control, and the web site states:

"After you drop a DockManager component on a designer Form from the Toolbox, the first thing to do is set the HostContainerControl. This is the control that will act as the hosting container for the docking system. This control may be a Form or any other type of container control."

I tried all of the "container" controls that I have (Panel, SplitContainer, BroupBox, TableLayoutPanel, etc), but the only option that I see for the HostContainerControl of my DockManager is the SplitContainer control. Am I missing something obvious?

Thanks.