Warning! Latest GPS Quickfix download is incorrect
Here in the Netherlands there are numerous people who ran into problems when they updated their TomTom device through TomTom Home.
There seems to be a problem with the quickfix data which causes the location to be off by 100 to 200 meters.
With a TomTom PND you can fix the problem by deleting the quickfix data in the ephem directory on your PND and performing a reset on the device so it looses the GPS data and it starts searching again for the correct location afterwards.
If you have a built in TomTom like the Carminat TomTom from Renault it is a little more difficult. I fixed it by doing the following.
I placed a backup from 2011 back to the SD card and I used Home to place the latest Navcore version back on the card so the unit in the car will be flashed again with clean data. After this my Carminat was showing the correct location again.