When writing data to a web server, my tests show HttpWebRequest.ReadWriteTimeout is ignored, contrary to the MSDN spec. For example if I set ReadWriteTimeout to 1 (=1 msec), call myRequestStream.Write() passing in a buffer that takes 10 seconds to transfer, it transfers successfully and never times out using .NET 3.5 SP1. The same test running on Mono 2.6 times out immediately as expected. What could be wrong?