I called tomtom because my Tomtom XL 340s wouldn't work on my vista 64bit. It gave me the error code 1058 I think. So I call the US tech support. The installer didn't install everything into Vista. I was missing folders according to tech support. I was told to uninstall, restart, defragment and reinstall.
Guess what - it didn't work.
I finally figured out that I could connect sort of by using the guest login not with my adminstrator. So then I went to my old man's house plugged it into his Vista 64bit laptop and presto, it works! Come to find out I disabled a tomtom spy service that tomtom relies on but tech support wasn't even hinting at that. I got my tomtom to work finally. It seems though I might return it for a Garmin if they treat us like this.