there seems to be a small bug in the filter-script GUI that makes it appear inside the edit box if I quote somebody. So far I've been unable to locate it, though.
edit: I think the problem is that the edit pane is an IFrame, so the script applies the createFilterConfigMenu to it as well, looking into it some more...
edit2: ok, I think I fixed it (although quick and dirty by checking if it's the edit-page before inserting the management-gui)
Installation link
edit3: it seems the bug only applied if you were useing the extenden wyswyg editor