I just found a very byzantine solution to an annoying problem.
I'm doing training this week and was finishing up my slides for an Impress class and accidentally undocked the Slides Pane. It was floating all over the place and I couldn't dock it again.
I understand that in some versions you can just drag the Slides Pane back to the edge and it'll redock. Sometimes you can hold down Ctrl and drag it back, and it'll redock.
But not with the December 2.0 update of OpenOffice.org.
I finally found the solution in one of the email@example.com mailing list archives.
You have to hold down Ctrl, then double-click the gray area next to the word slides in the slides pane. Not the top title bar Slides but the second time Slides appears.
See this screen shot. I'll do a better one when I'm done with the training class but you'll see what to do when you click on this thumbnail and look at the big screen shot. You have to hold down Ctrl, then double-click the circled area. This will dock your pane again.