I've spent a couple of hours faffing with this and I've had a root around the forum but I must be missing something obvious.

I had a macro that called an external URL for an API, got back some XML and iterated through the results.
(well, I actually called a custom extension which called the URL for me and returned XML)

Example:

     <xsl:variable name="EventXml" select="Eventbrite.User:User_ListEvents($ebAppKey, $ebUserKey, '', '', $eventStatuses, '')" />
     <xsl:for-each select="ucomponents.xml:Parse($EventXml)//events/event">
   .... stuff here ..
     </xsl:for-each>

Example of XML returned (simplified):

<?xml version="1.0" encoding="UTF-8" ?>
<events>
  <event>
        <id>1768877761</id>
                 <start_date>2011-08-03 13:00:00</start_date>
        </event>
   <event>
     <id>1234</id>
                 <start_date>2010-09-01 11:00:00</start_date>
        </event>
</events>

All was fine, until I realised high traffic site = many API calls.
So FeedCache2 to the rescue. Great. :)

Now the XML is in a file stored locally (App_Data/FeedCache/myfilename.xml).
My macro can load the XML. Then filter the events by their 'start date' - so I can display events past, future or all events.

The problem?

If I "count" the number of event nodes, it works and I get '2' back. Great!
But when I try to foreach iterate through them using the same syntax, it fails.

    <!-- File location -->
    <xsl:variable name="fileLocation" select="'C:\inetpub\wwwroot\App_Data\FeedCache\AllEvents2.xml'"/>
     <!-- Get cached data -->
    <xsl:variable name="FileXml" select="umbraco.library:GetXmlDocument($fileLocation, 'false')" />
  
    <!-- Get the correct nodes based on if we're only meant to be showing all, previous or future events -->
    <xsl:variable name="EventXml">
      <xsl:choose>
        <xsl:when test="/macro/showEvents != '' and /macro/showEvents = 'future'">
          <xsl:copy-of select="$FileXml//events [umbraco.library:DateGreaterThanOrEqualToday(event/start_date)]"/>
        </xsl:when>
        <xsl:when test="/macro/showEvents != '' and /macro/showEvents = 'past'">
          <xsl:copy-of select="$FileXml//events [umbraco.library:DateDiff(umbraco.library:CurrentDate(), event/start_date, 's') &gt; 0]"/>
        </xsl:when>
        <xsl:otherwise>
          <xsl:copy-of select="$FileXml//events"/>
        </xsl:otherwise>
      </xsl:choose>
    </xsl:variable>
     
  <xsl:value-of select="count(ucomponents.xml:Parse($EventXml)/*)"/>

Filtering the events by date works fine and the content of $EventXml is correct.
The 'count' statement above displays "2" - as there are two <event> nodes.

But this next line fails:

<xsl:for-each select="ucomponents.xml:Parse($EventXml)/*">

Like so:

Error parsing the XSLT:
System.OverflowException: Value was either too large or too small for an Int32. at System.Convert.ToInt32(Double value) at System.Convert.ChangeType(Object value, Type conversionType, IFormatProvider provider) at System.Xml.Xsl.Runtime.XmlQueryRuntime.ChangeTypeXsltArgument(XmlQueryType xmlType, Object value, Type destinationType) at System.Xml.Xsl.Runtime.XmlQueryContext.InvokeXsltLateBoundFunction(String name, String namespaceUri, IList`1[] args) at (XmlQueryRuntime {urn:schemas-microsoft-com:xslt-debug}runtime, XPathNavigator {urn:schemas-microsoft-com:xslt-debug}current) at Root(XmlQueryRuntime {urn:schemas-microsoft-com:xslt-debug}runtime) at System.Xml.Xsl.XmlILCommand.Execute(Object defaultDocument, XmlResolver dataSources, XsltArgumentList argumentList, XmlWriter writer) at System.Xml.Xsl.XslCompiledTransform.Transform(IXPathNavigable input, XsltArgumentList arguments, TextWriter results) at umbraco.macro.GetXsltTransformResult(XmlDocument macroXML, XslCompiledTransform xslt, Dictionary`2 parameters) at umbraco.presentation.umbraco.developer.Xslt.xsltVisualize.visualizeDo_Click(Object sender, EventArgs e)

I've tried masses of syntaxes. I can only think that the foreach fails because there is no 'root' node in the results after I get the Events I want (by date).
As the XML will look like this:

  <event>
     <id>1768877761</id>
                 <start_date>2011-08-03 13:00:00</start_date>
        </event>
   <event>
     <id>1234</id>
                 <start_date>2010-09-01 11:00:00</start_date>
        </event>