Transfer From One FTP To Another - Destination File Corrupt

I'm transferring from one FTP (a Dev site) to another FTP (a Test site). Spare me the thoughts of changing this process. In any case, here's my method:

Public Function TransferFile(originalFile As String, destinationFile As String) As String
Try
'FileStream for holding the file
Dim uploadRequest As FtpWebRequest = WebRequest.Create(destinationFile)
uploadRequest.Method = WebRequestMethods.Ftp.UploadFile
[Code] .....

This works perfectly for ASPX files and their .vb code behinds. When we try to transfer .DLL files, they show up on the server as 0 bytes, and sometimes actually transfer. The problem is that, despite being the same size as the original, they act as if they are corrupt.