If you want to have multiple main menus on the page, set alwaysvisible=1, along with the position properties (e.g., top=, left=, screenposition=), in the js menu code that your php script outputs.
If you're using position=relative, are you putting the other menus you want on the page in other cells of the table? If you could put a test page up so we can see what you are attempting it would help.