How to add a custom header

[salvador21]

I have (almost) successfully added a custom header div (235px high) which replaces the vBulletin logo. (see image 1 attached)

My problem is that it is screwed up in ie7, in that the toplinks go beneath the header instead of staying at the top as with all other borrowers. (see image 2) I can fix this by repositioning them, but there still a large area around the navbar that shouldn't be there( image 3)

I did this by trial and error, so hopefully somebody can tell me what I've done wrong.

Here is the code I am using:

<div class="above_body"> <!-- closing tag is in template navbar --><div id="header" class="floatcontainer doc_header">
    <!--CUSTOM HEADER ADDED--><div style="height:235px;
background-image: url(x-header/test-header.jpg);
"></div><!--/CUSTOM-->
    <!--VBULLETIN LOGO COMMENTED OUT
    <vb:if condition="$stylevar['titleimage']"><div><a name="top" href="{vb:link forumhome}" class="logo-image"><img src="{vb:stylevar titleimage}" alt="{vb:rawphrase x_powered_by_vbulletin, {vb:raw vboptions.bbtitle}}" /></a></div></vb:if> --><!--/VBULLETIN LOGO COMMENTED OUT-->

reposition toplinks for ie7:

<div id="toplinks" class="toplinks" style="position:relative;
top:-235px;">

This must be a very basic customisation, I hope somebody can please help me, thanks