Match table th widths with td in wordpress

Question

I'm working on some styling in Wordpress with WP e-Commerce and in the checkout page there is a table in which the table headers are all getting left justified and not becoming the width of each of their columns. When I try the HTML code without the CSS it works fairly well but there is so much CSS being applied that I cannot figure out what is causing it, exactly.

Please see the HTML code in question below.

Any thoughts on how to find the culprit?

<table class="checkout_cart">
    <tbody>
        <tr class="header">
            <th colspan="2">Product</th>
            <th>Quantity</th>
            <th>Price</th>
            <th>Total</th>
            <th>&nbsp;</th>
        </tr>
        <tr class="product_row product_row_0 alt">
            <td class="firstcol wpsc_product_image wpsc_product_image_0">   <img src="31x31.jpg" alt="Spreading the Light" title="Light" class="product_image">   </td>
            <td class="wpsc_product_name wpsc_product_name_0">  <a href="http://hailefinephotography.com/products-page/inner-aperture-fine-art-note-cards/spreading-the-light/">Spreading the Light</a>  </td>
            <td class="wpsc_product_quantity wpsc_product_quantity_0">
                <form action="/store/checkout/" method="post" class="adjustform qty">  
                    <input type="text" name="quantity" size="2" value="1">  
                    <input type="hidden" name="key" value="0">  
                    <input type="hidden" name="wpsc_update_quantity" value="true">  
                    <input type="submit" value="Update" name="submit">  
                </form>
            </td>
            <td><span class="pricedisplay">$5.00</span></td>
            <td class="wpsc_product_price wpsc_product_price_0"><span class="pricedisplay"><span class="pricedisplay">$5.00</span></span></td>
            <td class="wpsc_product_remove wpsc_product_remove_0">
                <form action="/store/checkout/" method="post" class="adjustform remove"> 
                    <input type="hidden" name="quantity" value="0">  
                    <input type="hidden" name="key" value="0">  
                    <input type="hidden" name="wpsc_update_quantity" value="true">  
                    <input type="submit" value="Remove" name="submit">  
                </form>
            </td>
        </tr>
    </tbody>
</table>

Answer 1

You have 5 headers (th), but 6 colums below (td)