Connection string from web.config - ok in debug but not when published

Hi,

I have an Web Service project, and for the purposes of testing I have a web method that simply connects to the Database (SQLExpress on my local machine using SQL authentication), and returns a dataset. I am storing the connection string in the web.config file. I have another project which consumes the web service, and when I step through this one and enter the web method, the connection string is null so it fails to return anything.

The code in the web.config looks like:

   
   
                 connectionString="Data Source=PC\SQLEXPRESS; User Id=user; Pwd=password; Initial Catalog=db; Min Pool Size=5; Max Pool Size=75; Pooling=True"/>
   
 
The code I'm using in the web method to access this looks like:

System.Configuration.Configuration rootWebConfig = System.Web.Configuration.WebConfigurationManager.OpenWebConfiguration("/MyWebSiteRoot");
System.Configuration.ConnectionStringSettings connString;

connString = rootWebConfig.ConnectionStrings.ConnectionStrings["ConString"];

As I say - when I Debug the Web Service on it's own it works fine, but when run from a browser on it's own (http://localhost/MyProject/MyWebService.asmx) it does not return anything, and when I've debugged it from another project that consumes it this is because the connection string is null.
Any thoughts?