Hmm, at the bottom of the static pages editor, it says "all HTML allowed" - which tags give you problems there?
Anway, you could make your own pages wrapped into Geeklog like this:
<?php
require_once ('lib-common.php');
echo COM_siteHeader ('menu');
echo COM_startBlock ("Some title"

; // optional - will wrap your page in a block
?>
<!-- your HTML stuff here -->
<?php
echo COM_endBlock(); // again, optional
echo COM_siteFooter();
>?
bye, Dirk