Sort doesn't seem to sort

I'm learning XML and running trivial examples from a book.  However, I
stumbled on a problem with this XSL code snippet:

      <xsl:for-each select="//vendor" >
      <xsl:sort select="vendor_name"/>
      <h2><xsl:value-of select="vendor_name"/></h2>
      </xsl:for-each>

Within the XML doc, there are vendor names that appear in the following
order in the XML doc:

Conners Chair Company
Just a Vendor
Wally's Wonderful World of Furniture
Crazy Marge's Bed Emporium
Zu Zu's Pedals

When I process the doc with IE 6.0, the vendor names are output in this
order:

Wally's Wonderful World of Furniture
Just a Vendor
Zu Zu's Pedals
Conners Chair Company
Crazy Marge's Bed Emporium

This isn't the expected alphabetical order output.  What gives?


 XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list