Hello Christoffer,
I suppose you are talking about nested RadDocks. We added support for nested docks (Dock in Zone in Dock in Zone etc.) in the current official release - Q2 2009 SP1 (2009.2.826 version).
Problems with nested docks have not been reported, and you will not have any troubles with the implementation this specific scenario.
Kind regards,
Pero
the Telerik team