Asynchronous Timeout possible?, C# WebService, VB Windows Client.

Boy, not even sure what forums to post this to...

My coworker claims he witnessed an Asynchronous callback timeout to a C# 2005 webservice, using an app written in Flex. The claim is that he only sees it after 6 hours or so.

My particular client app is a VB.NET 2005 app, declaring the WebService Object "WithEvents".

The 1st call to the xxxxAsync member by the VB client causes the C# service to execute a .WaitOne() function.

Some time later, the thread is awoken by another member which executes the .Set() function. It is the execution of this function that causes the VB client to receive the xxxxCompleted Event.

Consider the time between the .WaitOne() execution and the .Set() execution (within the context of the C# WebService). This is effectively the duration of the Asynchronous WebService call. If this duration is not too long, nothing bad happens.

However the claim is that IIS may itself be timing-out if this duration is many hours long, and returning some kind of 404 error or some such.

I have not seen this behavior manifest itself on the VB client, but presumably I would see the xxxCompleted Event get fired in this case? In which case, how would I know an IIS error had occurred?

Hope this makes sense,

Thanks!