MY12 Navigation Issue

[Spook]

Has anyone had problems with their OEM "WhereIs" navigation system regularly needing to be re-calibrated? Mine will lose its position randomly, sometimes it will work for a few minutes other times for hours. Only started happening after I disconnected the power while doing the nav hack. I have gone through the re-calibration process but am I missing something else?
Better yet has anyone been able to upgrade the firmware on their system (to another brand Tom Tom, Garmin) using the standard screen and disc drive, or are 3rd party components required?