export SAL_USE_VCLPLUGIN=gen
This will make OO.org fallback to its native theme ... ugly as sin, but usable.
Note that if you are having the opposite problem--that you can't get OO.org to render with your GTK theme--then try adding:
export OOO_FORCE_DESKTOP=gnome
export SAL_USE_VCLPLUGIN=gtk
instead. This suggestion is from the #! forums and Urukrama's blog.
There are a few other usability issues I'm having with aud-Default , but I'm willing to work at it some more given the sweet way it renders entries in fbpanel's taskbar.