A) Make sure that the APN name is correct（the APN name dependent on your telecom carrier,please contact your carrier for the APN Name).
B) Make sure that other non-OSCall WI-FI and GPRS function is turned off.
C) Make sure that GPRS is connected. The blue icon will appear on Standby screen that indicates GPRS is available online.
D) If the blue icon appear on Standby screen,but can not use GPRS function,try closing some background processes if any（Multiple processes may take some GPRS traffic，lead to slow or unable to access the Internet）, for the iTouch, press the Home key twice to enter phone background.