Sharepoint webpart cannot read httpwebresponse from asp.net page

Question

I have a sharepoint webpart that makes an httpwebrequest to an ASP.NET web page. The webpage polls a database and spits out an rss feed as xml. Whenever I try to get the response from the page I am getting an IO exception : "Unable to read data from the transport connection: The connection was closed." As of right now I am not trying to do anything complicated with the stream just read it and write the text to a label in a panel on the webpart. Here is the code

request = (HttpWebRequest)WebRequest.Create
("http://xxhrnsp-asm/_layouts/1033/custom/RetrieveRSS.aspx" + 
sourceStr + startDateStr + endDateStr);

// set the method
request.Method = "GET";

// use current users credentials
request.Credentials = CredentialCache.DefaultCredentials;

// set keep alive (may not be needed)
request.KeepAlive = false;

// set the timeout REALLY high.  (if it takes this long might as well not use it)
request.ReadWriteTimeout = request.Timeout = 60000;

// get the response
response = (HttpWebResponse)request.GetResponse();

if (response != null)
{
    StreamReader rssReader = new StreamReader(response.GetResponseStream(), Encoding.UTF8);
    String rssString = rssReader.ReadToEnd();

    // do something with the response
    ResultsPanel.Controls.Remove(ResultsLabel);
    ResultsPanel.Height = 720;
    ResultsLabel.Text = rssString;
    ResultsPanel.Controls.Add(ResultsLabel);

    // cleanup
    rssReader.Close();
    response.Close();
}

The aspx page itself works fine. I can go to a browser and type in the URL and an RSS feed based on the parameters pops up. The line that reads String rssString = rssReader.ReadToEnd(); is the one that is causing the errors.