I wasn’t able to figure out why the gap appears there. I ran the page through the W3C validator and fixed a lot of validation errors, mostly elements like <link...>,
and <input...> that weren’t properly closed, and the javascript in the weblogin.inc.php file has to have CDATA blocks put around it:
<script type="text/javascript">
//<![CDATA[
...
//]]>
</script>
Giving the #WebLoginLayer0 form (or the table) a negative top margin pulled it up in FF but not Safari. For some reason there is a gap from the top of the <div> element to the top of the form and its enclosing table. The top of the <div> element is where it should be.
Personally, I don’t like the sidebar layout using an unordered list for the entire sidebar. I prefer to have individual <div> elements for each block, and keep the unordered list for... well, lists. I suspect that may be playing a part in this, but I really don’t know.