jquery - jquery-1.4.2.min.js
tablesorter - 2.0.3

How to reproduce.

Using the following table, clicking on the "works" header works fine, clicking on the "causes error" header causes an "parsers[i] is undefined" error


<table id="myTable">
<thead>
<tr>
    <th>works</th>
    <th>causes error</th>
</tr>
</thead>
<tbody>
<tr>
<td colspan="2">a</td>
</tr>
<tr>
    <td>aaa</td>
    <td>bbb</td>  
</tr>
</tbody>
</table>


As shown below, when the colspan row is not the first row in the table, things seem to work fine.


<table id="myTable">
<thead>
<tr>
    <th>works</th>
    <th>now works fine</th>
</tr>
</thead>
<tbody>
<tr>
    <td>aaa</td>
    <td>bbb</td>  
</tr>
<tr>
<td colspan="2">a</td>
</tr>
</tbody>
</table>