Help with width problem

[MRGTB]

I'm having a problem with a hack on my site that is driving me up the wall. I've tried everything I can think off and nothing works.

After adding a side bar hack, I've noticed that the width of the sidebar and the forum on the forumhome page is slightly less barrow that the navbar width on both right and left sides

Here is the code in question that controls the width:

<table cellpadding="$stylevar[cellpadding]" cellspacing="0" border="0" width="$stylevar[outertablewidth]" class="page" align="center">
<tr>
<td width="20%" valign="top">

I've also attached an image so you can see what I mean exactly, it's the same on both left and right sides. You can view my forum home on my signiture to see it better.

How can this code be edited to fix this so it's full width to match the navbar on both sides like it should be.