Thread:Project:Support desk/Table column unsortable when fields begin with $

I've got a table with 3 columns that I want to be able to sort. The first and second columns list a bunch of values that all begin with the $ character, followed by a single letter. I cannot seem to get them to sort (i.e., nothing happens when I press the sorting arrows), although the third column (simple text) sorts just fine. Is there a way to solve this?


 * Mediawiki 1.15.1
 * PHP 5.1.6
 * MySQL 5.0.22

Below is the table: