Colspan changes from colspan="3" to colspan="2" once JS kicks in...

HI, I have a a large table with 2600+ entries. I am using the wonderful header sorting features. I have it setup like so:

<thead>
			<tr>
				<th colspan="1" rowspan="2">
					ROAD</th>
				<th colspan="1" rowspan="2">
					MILES</th>
				<th colspan="3" rowspan="1">
					BENEFIT</th>
				<th colspan="2" rowspan="1">
					RISK</th>
				<th colspan="1" rowspan="2">
					RECOMMENDATION</th>
			</tr>
			<tr>
				<th>
					VEG</th>
				<th>
					FIRE</th>
				<th>
					SOCIAL</th>
				<th>
					WATERSHED</th>
				<th>
					WILDLIFE</th>
			</tr>
		</thead>

Once the page renders in IE, FF and Chrome it changes to (using Firebug... the view source still looks correct):

<thead>
<tr role="row">
<th class="ui-state-default" colspan="1" rowspan="2" role="columnheader" tabindex="0" aria-controls="taptable" style="width: 79px;" aria-sort="ascending" aria-label=" ROAD: activate to sort column descending">
<th class="ui-state-default" colspan="1" rowspan="2" role="columnheader" tabindex="0" aria-controls="taptable" style="width: 68px;" aria-label=" MILES: activate to sort column ascending">
<th colspan="2" rowspan="1"> BENEFIT</th>
<th colspan="2" rowspan="1"> RISK</th>
<th class="ui-state-default" colspan="1" rowspan="2" role="columnheader" tabindex="0" aria-controls="taptable" style="width: 163px;" aria-label=" RECOMMENDATION: activate to sort column ascending">
</tr>
<tr role="row">
<th class="ui-state-default" role="columnheader" tabindex="0" aria-controls="taptable" rowspan="1" colspan="1" style="width: 56px;" aria-label=" FIRE: activate to sort column ascending">
<th class="ui-state-default" role="columnheader" tabindex="0" aria-controls="taptable" rowspan="1" colspan="1" style="width: 78px;" aria-label=" SOCIAL: activate to sort column ascending">
<th class="ui-state-default" role="columnheader" tabindex="0" aria-controls="taptable" rowspan="1" colspan="1" style="width: 113px;" aria-label=" WATERSHED: activate to sort column ascending">
<th class="ui-state-default" role="columnheader" tabindex="0" aria-controls="taptable" rowspan="1" colspan="1" style="width: 95px;" aria-label=" WILDLIFE: activate to sort column ascending">
</tr>
</thead>

You can see that VEG is missing...

Any thoughts? Am I missing something?

Link to page with issue: http://www.fs.usda.gov/detailfull/plumas/home/?cid=stelprdb5424381&width=full