Commented Unassigned: An established connection was aborted by the server [2398]

When trying to download files from sftp, I am getting error:"__An established connection was aborted by the server__"
Comments: ** Comment from web user: ericbruno **

Hi,

first of all, thank you for providing this useful library.

I use version 2014.4.6.0, built from the source available in the Downloads section. I experience the same issue. Downloading any file above ~15k fails. Here's the code (skeleton with "real" values where applicable):

```
using (var sftp = new SftpClient(url, user, pw))
{
sftp.Connect();
sftp.SendKeepAlive();
sftp.OperationTimeout = TimeSpan.FromSeconds(3600);

var dirFiles = sftpClient.ListDirectory("outgoing"); // find one file: "outgoing/a.zip"

string remoteFile = dirFiles[0];
string localFile = @"C:\a.zip";

using (FileStream downloadFS = new FileStream(localFile, FileMode.Create, FileAccess.Write))
{
sftpClient.DownloadFile(remoteFile, downloadFS); // this is where the error occurs
}

sftp.Disconnect();
}
```
StackTrace:
```
at Renci.SshNet.Sftp.SubsystemSession.WaitOnHandle(WaitHandle waitHandle, TimeSpan operationTimeout)
at Renci.SshNet.Sftp.SftpSession.RequestRead(Byte[] handle, UInt64 offset, UInt32 length)\
at Renci.SshNet.SftpClient.InternalDownloadFile(String path, Stream output, SftpDownloadAsyncResult asyncResult, Action`1 downloadCallback)
at Renci.SshNet.SftpClient.DownloadFile(String path, Stream output, Action`1 downloadCallback)

```

__NOTE__
The connection, file listing, etc. works great. And there is no issue with small-size files. Sample __a.zip__ is about 120k, which doesn't look excessive. Curiously, I was able to download much larger files using a previous (2013.4.7.0) version of SSH.NET.

If there's another way of requesting a download, I'm happy to re-implement.

Thanks for any pointers/help.
Eric