This (or a very similar question) has been asked before but there was
no reply and I was hoping that someone might have the answer now:


I have WSE (2.0 SP2 and SP3) and occasionally (apparently at random)
this causes the following error:


System.InvalidOperationException: EndInvoke can only be called once
for each asynchronous operation.
   at
System.Web.Services.Protocols.WebClientAsyncResult.WaitForResponse()
   at
System.Web.Services.Protocols.WebClientProtocol.EndSend(IAsyncResult
asyncResult, Object& internalAsyncState, Stream& responseStream)
   at
System.Web.Services.Protocols.SoapHttpClientProtocol.EndInvoke(IAsyncResult
asyncResult)

This has been happening on a number of machines (Windows 2000 Server/
Windows 2003 Advanced Server/Windows XP SP2). My own development
machine, which has been fine, has also started developing this
problem. The servers are all using WSE 2 SP 2 and my own machine uses
WSE 2 SP3.

Does anyone know why this error may be occurring?

Thanks,

Nigel