Problems connecting to the Internet using the shield of TELEFONICA (M10)

Hi friends, last week I buy the GSM shield based on the M10 radio. The first tests was sending SMS and send calls using a SIM Simyo, with the examples code including in the library, and has worked good without problems, but when I tried to access the Internet using the example "Test Web Server: Create a webserver With Your GSM shield", and I look at the serial monitor to know the IP, I read IP: I don´t know why I can´t show the IP. I set the APN as follows: // APN data

define GPRS_APN "" // replace your GPRS APN

define GPRS_LOGIN "" // replace with your GPRS login

define GPRS_PASSWORD "" // replace with your GPRS password

This is the way indicated by the phone company, But it does not work. I want to turn on and off the heating in my country house and receive an E-mail if the door is open, via internet (GPRS). Greetings and thanks.