I have been trying to parse the below 
XML file (kuler rss feed). I have read the various posts on this site but am unable to piece them together.
I specifically want to extract the child(or siblings) nodes of the element <kuler:themeItem>.
However I am getting an exception :
Namespace Manager or XsltContext needed. This query has a prefix, variable, or user-defined function.
Pl help : C# 3.0 net framework 3.5
RSS feed snippet:
<?xml version="1.0" encoding="UTF-8" ?> 
- <rss xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:kuler="http://kuler.adobe.com/kuler/API/rss/" xmlns:rss="http://blogs.law.harvard.edu/tech/rss" version="2.0">
- <channel>
  <title>kuler recent themes</title> 
  <link>http://kuler.adobe.com/</link> 
  <description>most recent themes published on kuler (1 to 20 of 332518)</description> 
  <language>en-us</language> 
  <pubDate>Wed, 07 Apr 2010 08:41:31 PST</pubDate> 
  <lastBuildDate>Wed, 07 Apr 2010 08:41:31 PST</lastBuildDate> 
  <docs>http://blogs.law.harvard.edu/tech/rss</docs> 
  <generator>Kuler Services</generator> 
  <managingEditor>
[email protected]</managingEditor> 
  <webMaster>
[email protected]</webMaster> 
  <recordCount>332518</recordCount> 
  <startIndex>0</startIndex> 
  <itemsPerPage>20</itemsPerPage> 
- <item>
  <title>Theme Title: Muted Graph</title> 
  <link>http://kuler.adobe.com/index.cfm#themeID/856075</link> 
  <guid>http://kuler.adobe.com/index.cfm#themeID/856075</guid> 
- <enclosure xmlns="http://www.solitude.dk/syndication/enclosures/">
  <title>Muted Graph</title> 
- <link length="1" type="image/png">
  <url>http://kuler-api.adobe.com/kuler/themeImages/theme_856075.png</url> 
  </link>
  </enclosure>
  <description><img src="http://kuler-api.adobe.com/kuler/themeImages/theme_856075.png" /><br /> Artist: tischt<br /> ThemeID: 856075<br /> Posted: 04/07/2010<br /> Hex: F1E9B2, 3D3606, 2A3231, 4A0A07, 424431</description> 
- <kuler:themeItem>
  <kuler:themeID>856075</kuler:themeID> 
  <kuler:themeTitle>Muted Graph</kuler:themeTitle> 
  <kuler:themeImage>http://kuler-api.adobe.com/kuler/themeImages/theme_856075.png</kuler:themeImage> 
- <kuler:themeAuthor>
  <kuler:authorID>216099</kuler:authorID> 
  <kuler:authorLabel>tischt</kuler:authorLabel> 
  </kuler:themeAuthor>
  <kuler:themeTags /> 
  <kuler:themeRating>0</kuler:themeRating> 
  <kuler:themeDownloadCount>0</kuler:themeDownloadCount> 
  <kuler:themeCreatedAt>20100407</kuler:themeCreatedAt> 
  <kuler:themeEditedAt>20100407</kuler:themeEditedAt> 
- <kuler:themeSwatches>
- <kuler:swatch>
  <kuler:swatchHexColor>F1E9B2</kuler:swatchHexColor> 
  <kuler:swatchColorMode>rgb</kuler:swatchColorMode> 
  <kuler:swatchChannel1>0.945098</kuler:swatchChannel1> 
  <kuler:swatchChannel2>0.913725</kuler:swatchChannel2> 
  <kuler:swatchChannel3>0.698039</kuler:swatchChannel3> 
  <kuler:swatchChannel4>0.0</kuler:swatchChannel4> 
  <kuler:swatchIndex>0</kuler:swatchIndex> 
  </kuler:swatch>
My Code so far:
static void Main(string[] args)
    {
        const string feedUrl =
            "http://kuler-api.adobe.com/rss/get.cfm?listtype=recent&key=xxxx";
        var doc = new XmlDocument();
        var request = WebRequest.Create(feedUrl) as HttpWebRequest;
        using (var response = request.GetResponse() as HttpWebResponse)
        {
            var reader = new StreamReader(response.GetResponseStream());
            doc.Load(reader);
        }
        XmlNodeList rsslist = doc.SelectNodes("//rss/channel/item/kuler:themeItem");
        for (int i = 0; i < rsslist.Count; i++)
        {
            XmlNode rssdetail = rsslist.Item(i).SelectSingleNode("kuler:themeTitle");
            string title = rssdetail.InnerText;
            Console.WriteLine(title);
        }
    }
}