strange cache issue with HttpWebRequest - asp.net

Question

We have a web app that calls a url of an outside search provider to load search results. Each time our page is hit it can pass in a current page number. This page number is included in the url sent to the 3rd party. I've noticed that while they report 45 pages of results, if I go to one of the pages that includes their results and then try to navigate to another page that has additional results from them, the same results from the first page are loaded.
I tried setting up my HttpWebRequest object to disable caching but everything I've tried doesn't seem to work. And, considering the url changes each time due to the page number, I wouldn't think that it would really be a cache issue. But here's where it gets interesting.
If I copy the url that I'm retrieving in code and paste it into chrome it loads the correct results. I then refresh the web app page and it too now loads the results for that page. This makes no sense to me. The code is running locally but since it's running within asp.net, it isn't using chrome to create the web request, so why does this happen?
Here's the code I have that calls the url and returns the result.
public static string FetchPage(string url)
{
//Specify the encoding
Encoding enc = System.Text.Encoding.GetEncoding(1252);
HttpWebRequest.DefaultCachePolicy = new HttpRequestCachePolicy(HttpRequestCacheLevel.Default); ;
//Create the http request
var request = (HttpWebRequest)WebRequest.Create(url);
request.CachePolicy = new HttpRequestCachePolicy(HttpRequestCacheLevel.NoCacheNoStore);
//Create the http response from the http request
var httpWebResponse = (HttpWebResponse)request.GetResponse();
//Get the response stream
var responseStream = new StreamReader(httpWebResponse.GetResponseStream(), enc);
//Read the response stream
string htmlStream = responseStream.ReadToEnd();
//Close the web response
httpWebResponse.Close();
//Close the response stream
responseStream.Close();
return htmlStream;
}

Answer 1

Please try these following lines to set no-cache in both HttpWebRequest and WebResponse
For Request
Request.Headers.Set(HttpRequestHeader.CacheControl, "max-age=0, no-cache, no-store");
Request.CachePolicy = new System.Net.Cache.RequestCachePolicy(System.Net.Cache.RequestCacheLevel.NoCacheNoStore);
For Response
Response.Headers.Add(HttpRequestHeader.CacheControl, "no-cache");