ASP.NET 3.5 Stops responding

A client has complained about some legacy code that was written a while back. When the client uploads a file, the server takes the file and processes it. This is using the Script Services (Web Service). It appears that the file takes ~10 mi开发者_StackOverflownutes to finish and when it does, it responds back saying it finished. Unfortunately, I am getting no message on the browser side of either success or failure. I can see that the function finished, but the browser receives no notification of this event. I will be more than happy to provide more information as needed.

Thanks!