JQuery: Validation plugin breaks when changing from jquery 1.2.6 to 1.3.2

I recently upgraded from jQuery 1.2.6 to 1.3.2

Now on the page I am using the form validation plugin I am getting an exception:

[Exception... "'Syntax error, unrecognized expression: [@for='registration_primary_email']' when calling method: [nsIDOMEventListener::handleEvent]"  nsresult: "0x8057001e (NS_ERROR_XPC_JS_THREW_STRING)"  location: "<unknown>"  data: no]

      

        
        
        
      

    

This does not happen as of 1.2.6. Any idea what's going on?