issue with sat nav location
need bit of help
recently bought a pioneer hd1 bt. really like it and it makes it sound really great. dvd playback is quite good. people were charging around 200 for installation and parts and thanks to the guys off here I got the right parts and did it myself. saved about 160
anyway, having a little issue with my sat nav location though. the system says gps ok and is connected to a fair few satilites but for some reason the sat nav thinks am around 20 metres from where I am and on some occasions driving the wrong way
yesterday I messed about with it and changed my location to the correct road, pointed myself in the right way. turned the sat nav on to take me home and it worked perfectly. turned engine off jumped back in the car this morning half through the journey pressed map button and again am off track and according to the map-arrow am driving sideways.
the system has these data captures which am guessing help with calculating the direction travelling. am thinking to reset these and start again.
does anyone have any ideas to help me.