Clio TomTom Losing position etc...etc?

My Clio TomTom sat nav when stationary, finds the correct location, however the second i pull off the drive the sat nav doesnt keep up,then starts to go haywire rotating the map 180 degrees and you appear to be travelling backwards then the map will flick and rotate and the car will appear to be crabbing sideways. You can not plan a route, with all the map flipping and apparent signal loss as the the voice navigation will instruct you to do a u-turn on a motorway! I have tried a new, fully updated SD card and even fitted a new sat nav unit in the dash. I now have a new updated map system however the fault remains exactly the same. i am stumped has any one else had the same fault or atleast insight to a cure