The multiple header script only tells POD which file to use.
(It in it self doesn't mess up anything.)

The problem is to make the html-code in the header files and in the podvars.pm
match the table tags etc. from dmoz.

The different pages from dmoz has different tables, and this make this quite difficult.
You should also notice that explorer and netscape interprets the pages differently.
Pages that are visible in explorer, might be invisible with Netscape.

B.t.w. Nice site You have! Please tell us Your secrets to get traffic for it!