I've used ObjectDock, with autohide for years.  I decided to try out Ubuntu and run XP as a virtualbox.  Works fine except when I configure ObjectDock for "Hide off-screen when not in use".

I can see the dock (and use it) when I have the ObjectDock Properties open.  But as soon as I close properties, the dock hides (as it should) but a mouse-over will not make it reappear.

I should mention that it DOES hide/reappear properly when it's positioned on a side pannel.  It just won't reappear when I try to place the dock anyplace (horizontally) at the bottom of my screen.  How can I get this to work in VirtualBox?