HttpWebResponse: 404 not found error?

Hi,

I'm using HttpWebRequest/HttpWebResponse to communicate with a server to fetch data. The procedure also keeps track of cookies. In most case, it works fine. However, I got a weird error:

I use "Post" login the site, and then use "Post" to post new data. if I do not use proxy for the HttpWebRequest, everything works fine. However, once I use proxy for HttpWebRequest, if I try to get the HttpWebResponse, it returns an exception: 404 not found. But, when I check the server, the data is posted! and I happened to find an interesteing thing: if I put a break point at the line where I use HttpWebResponse to get the response, as long as I wait several seconds at the break point, the HttpWebResponse return "OK" (not the 404).

what could cause this problem?


thanks

bear