C# .NET - Special character ? appended when combres concatenates .cs or .js files

Hi,

Inconsistent behaviour in different environments.
combres.axd file is used to concatenate multiple cs files or js files.
In one environemnt the application works fine and  in the other it fails.

In the browser settings, I modified the encoding format to UTF-8, the application rendered properly.
When the same in ISO format failed.

This happens when application is hosted within cloud environment. The same combres works fine in all browsers in non cloud environment.

Is there any settngs i should consider. PLease advise

Thanks,
Santhosh