Have you ever experienced the problem, that your .NET CF application throws the following exception using a SSL Connection?
System.Net.WebException: Unable to read data from the transport connection (System.Net.Sockets.SocketException: Unknown error (0x0))
If this is the case, than you probably want to get the HotFix for Web Services over SSL for .NET CF 3.5.
Unfortunatelly this error exists with the .NET CF 2.0, where no fix is available and I’m not commenting this any further. 😉