WSE3 and VS2005 compact framework

[AndyBrew70]

Hi I have been attempting to implement a WSE3 secured web service which is invoked by my PDA based application using the compact framework however I cannot get my PDA based app to compile due to the following object not existing: System.Threading.SendOrPostCallback Is the compact framework not compatible with WSE3 or am I doing something wrong, incidentally the error actualy occurs within the Reference.cs file which is created by VS when referencing the web service. What is the best method to secure web services that are to be invoked by a PDA, originally we were thinking of HTTPS and our own username/password/pinnumber combination being passed through within each method call??? Thanks in advance Andy