I did a huge update a few weeks back on this device and ever since then in use it's sluggish to keep up to date with the vehicle position (and never was sluggish) and every 5 minutes or so when in a journey the screen goes blank and then restarts the journey. Then about 20 minutes in it completely shuts down and starts again. It's in the same car as it's always been powered through a direct wire connection, battery power is always full so it's not a power issue. The unit is now useless to me. Any thoughts as it was working fine until the update and I'm reluctant to do a hard reset and lose everything.