I wrote some ASP.NET web services that use JSON encoding, a la:
[WebInvoke()]
[OperationContract]
public int SetInformation(int recordid, string data)
{
This is a "security" feature that prevents the JSON from being returned from being able to be directly executed javascript inside an Eval statement. Or something very similar along these lines.
More information on this topic: http://encosia.com/a-breaking-change-between-versions-of-aspnet-ajax/ take a look at the section labeled Waiter, there’s a .d in my msg soup!