XSLT manipulating 'action' variable by inserting a '/' (forward slash) only when appending to onclick attribute hor an anchor tag

Hi there,

I am having a peculiar problem using XSLT in .NET v1.

Here is a snippet of the relevant XSLT:
<a>
<xsl:attribute name="href"><xsl:value-of select="./@url"/></xsl:attribute>
<xsl:attribute name="onclick">tvpop('<xsl:value-of select="./@url"/>');return false;</xsl:attribute>
<xsl:attribute name="target">new</xsl:attribute>
<xsl:variable name="sttitle" select="."/>
<xsl:value-of select="ms:rtnTitle(string($stdte),string($sttitle))" disable-output-escaping="yes"/>
</a>

And here is the relevant XML node that the above is transforming:
<title st="10/08/2007 1:20:00 AM" du="30" url="/guide/index.cfm?action=session_info&amp;event_id=18465952">Shopping for Love</title>

Putting these together gives the following HTML:
<a href="http://www.yourtv.com.au/guide/index.cfm?action=session_info&event_id=18465952" onclick="tvpop('http://www.yourtv.com.au/guide/index.cfm?action=/session_info&event_id=18465952');return false;" target="new">Shopping for Love</a>

If you look closely, the first time that the @url attribute is selected, the QS parameter outputs correctly: "action=session_info".  However, in the second select of the @url attribute(where it is used in the onclick event) this same value gets manipulated to 'action=/session_info'.

Why is it doing this?  I have tried output escaping, hard coding the 'action=session_info' part of the url but when the transformation is done, it always puts a '/' before session_info.

Can anybody help?  Is this a bug? Is 'action' some sort of key word?