if your desktop has multiple screens you can move an application to another screen after you start it. with audacious the playlist window stays in the original screen and you must restart audacious in the new screen for it to follow.
Don't restrict bugs without any reason, please. Just leave the checkboxes alone.
I have the same problem with Fluxbox 0.9.15.1-gentoo-r1
This behaviour is not due to the way that audacious is packaged in Gentoo. Please use the upstream bugtracker provided in the URL field.