Tx; You might try " Restore defaults" to remove the update.
1. Save all stored data to SD card and remove it.
2. Go to the "Product Manual" on the "Set Menu Tab".
3. Highlight "Restore Defaults" tab follow inst.
4. Power down unit and restart unit.
5. Check GPS status let the unit run for 15 min check GPS status. If unit function is OK Power off. If NOT call HB.
6. Down load "NEW" update from HB to "NEW" SD card.
7. Upload as per Product Manual inst.
Post outcome to Forum.
Good Luck and Enjoy
Roddy