You have the name right.
I would suggest clearing the cache, which is explained here http://corkyo.wincustomize.com/Articles.aspx?AID=82461
In your case, you would save your theme if you want > unload ObjectDock > follow the directions to clear the cache (just delete the "ObjectDockPlus" or "ObjectDock" cache folder to clear) > reload ObjectDock, which will load with the default settings.
From the default settings, you should be able to create a new tabbed dock and work with the dock to customize it via that docks "Dock Settings" dialog.
I do not run dual monitors, so I am not sure on support for dual monitors. Perhaps someone with experience in that will drop by and comment.
Note - the link in comment #2 will give you the proper placement of the skin folders so you can work with them. For backgrounds you will want to make sure you are placing a folder bearing the name of the background theme (which must include the background images and the "background.ini" file) inside the "C:\Program Files\Stardock\ObjectDock\Backgrounds" folder.
You will then be able to use the specific dock's "Dock Settings\Appearance" section to select a tabbed dock background.
I hope this helps.