Did you happen to save the theme using the "Dock Settings > General category > Save Theme as" function?
If so, you can try to reload the theme while connected to the second monitor again.
Failing this, and if the theme does not show up again when connected to the monitor, I believe you are out of luck.
The only possible trick would be to look in the ObjectDock cache folder, and see if the ".ini" files have the location coordinates for the tabbed dock you are referring to. If so, you may be able to change the coordinates to the single monitor to get it to load (I believe this would work if for some reason ObjectDock thought it was still loading the dock successfully when the program loads up, and did not change the cache files).
The ObjectDock cache folder is found in "C:\Documents and Settings\USERNAME\Local Settings\Application Data\Stardock" folder (note - the "Local Settings" folder is a hidden folder, so you will need to have "Show hidden files and folders" selected in the Folder Options\View tab).
For a mini tutorial discussing the cache files, you can go here http://corkyo.wincustomize.com/Articles.aspx?SID=5463&AID=82461