You need to remove some of the tables that are used purely for decorative effect. For example, your <yabb main> section looks like this:
<table class="bordercolor" cellspacing="0" cellpadding="0" width="98%" align="center" bgcolor="#6394bd" border="0">
<tr>
<td>
<table class="bordercolor" cellspacing="1" cellpadding="0" width="100%" align="center" bgcolor="#6394bd" border="0">
<tr>
<td>
<table cellspacing="0" cellpadding="10" width="100%" align="center" bgcolor="#ffffff" border="0">
<tr>
<td valign="top" width="100%">
<yabb main>
</td>
</tr>
</table>
</td>
</tr>
</table>
</td>
</tr>
</table>
But the equivalent section from my
Flypaper board looks like this:
<table border="0" width="100%" cellspacing="0" cellpadding="0" class="bordercolor" align="center">
<tr>
<td valign="top" width="100%">
<yabb main>
</td>
</tr>
</table>
Haven't got time at the moment to go through your whole template and do it for you, but hopefully that should give you the idea!

PS My board has 5% left and right margins, otherwise it would be as wide as Overseer's.