I just used iGuidance on a 2 hour trip. On the way there I used the internal GPS and it was poor at best. It wouldn't refresh unless I tapped the screen and even then it was jumpy and wouldn't move while I was driving. It seemed like the refresh rate with the internal GPS was off or not up to what the program needs. On the wy home I used my Holux bluetooth GPS and that worked perfectly as it always has. I am a big fan of the internal GPS for things like Google maps or doing a Live search to find stuff "near my location" etc but so far, it doesn't seem to be nearly as capable as the Holux. Just a little heads up
And yes, I tried with Google Maps running in the background as well to see if that helped and it didn't.