No I really don't I'd just be guessing, I just know that sometimes clearing out the cache solves some problems.
The best thing to do is keep yourself positioned by saving your themes regularly, then you don't have to re-create them. Saving and loading themes is done within the Object Dock configuration window, click on "Themes" item on the left side, click on "Save current dock" (or "Load previous dock") button towards the bottom.
Glad it worked for you.