Ok, I'm using an xslt stylesheet to upgrade the Silva Document xml for documents with Tropos version 1 forms  to Tropos version 2 forms.  I had already upgraded a couple sites, which apparrently worked fine.  On the last site I upgraded, none of the xslt would not catch the <form> tag.  I finally tracked it down to the <doc> tag in the xml.

The documents that correctly translated did not have a default namespace.  The documents that didn't had a doc tag like:

<doc xmlns="http://xml.infrae.com/document/0.9.3">

My stylesheet, which basically looked like:

<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
                version="1.0">
  <xsl:output method="xml" version="1.0" indent="no" />
  <xsl:template match="form">
    <xsl:element name="form" use-attribute-sets="form-attrs">
    </xsl:element>
  </xsl:template>
  <xsl:template match="node() | @*">
    <xsl:copy>
      <xsl:apply-templates select="node() | @*"/>
    </xsl:copy>
  </xsl:template>
</xsl:stylesheet>

Did not work with documents that declared a default namespace.  To fix this, the stylesheet was modified to have two <xsl:template match="form"> blocks.  Because it was the default namespace, I didn't know how to make xsl:template match it.  So, I named the namespace in the xsl:stylesheet tag.  The new stylesheet looks like this:

<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
                xmlns:doc="http://xml.infrae.com/document/0.9.3"
                version="1.0">
  <xsl:output method="xml" version="1.0" indent="no" />
  <xsl:template match="form|doc:form">
    <xsl:element name="form">
    </xsl:element>
  </xsl:template>
  <xsl:template match="node() | @*">
    <xsl:copy>
      <xsl:apply-templates select="node() | @*"/>
    </xsl:copy>
  </xsl:template>
</xsl:stylesheet>

And it works!