Enable Wifi. The iPod and iPad (Wifi) can only determine your position via WiFi triangulation.
If your position cannot be determined, connect this device to the internet (via WiFi). This will allow the device to update the positioning-database for your region. After successfully determining your positiong you will no longer require an internet connection (but need to leave WiFi enabled).
Please understand that the position is determined via the devices hardware and are outside of the control of this app.