Anybody else having this problem? I am on a jailbroken 8G 3G in the UK. Today i went to use the maps feature for the first time since upgrading to iOS4.0 and realized that it is having a REALLY hard time locating me (miles off sometimes) and when I drive the blue dot doesn't move. In fact, lots of the time the pulsing circle around the dot just goes away! Data is otherwise working fine on the phone. Suggestions?