C# Express 2010 Multi-Threading

I have a windows app that I have been running in c# Express 2008 for a year and have been trying to convert it over the last few days to 2010. The problem 开发者_如何学CI am having is it is a multi-threaded application that has to run a series of code every second. What it does is have a main thread, that calls 3 worker threads, waits for them to finish then does some additional processing, sleeps till 1 second and runs again.

The problem is part of the code can call a web service that takes 8 seconds to respond, so this bit of code gets called using ThreadPool.QueueUserWorkItem. The problem is when running in 2010 when this part of the code gets called the main thread continues to run but when it awakens the sub threads it hangs until the Threadpool method finishes running.

This never happens in 2008. Any suggestions? So far I put that bit of code in it's own thread rather than using Threadpool but same issue.

I ported quite a lot of apps from VS 08 to 10 when I updated my IDE, Most of the time I've had no problems as long as all the values in the 'Properties' tab (do you call it a tab) look OK. Sometimes Visual Studio will automatically fix anything that's wrong, but other times, you've gotta go in and edit manually.

Do you get any warnings in your error window?