I have an ASMX Web Service that has its code entirely in a code-behind file, so that the entire contents of the .asmx file is:

<%@ WebService Language="C#" CodeBehind="~/App_Code/AddressValidation.cs" Class="AddressValidation" %>

On my test machine (Windows XP with IIS 5), I set up a virtual directory just for this ASP.NET 2.0 solution and everything works great. All my code is separated nicely and it just works.

However, when we deployed this solution to our Windows Server 2003 development environment, we noticed that the code only compiled when all of the code was dropped directly into the .asmx file, meaning that the solution didn't work with code-behind. We can't figure out why this is happening.

One thing that's different about our setup in our development environment is that instead of creating a separate virual directory just for this solution, we dropped it into an existing directory that runs a classic ASP application. So here we have a folder with an ASP.NET 2.0 application within a directory that contains a classic ASP application. Granted, everything in the ASP.NET 2.0 application works if all of the code is within the .asmx file and not in code-behind, but we'd really like to know why it's not recognizing the code-behind files and compiling it correctly.