Not sure but I used to have a TomTom with no problems at all, and the gps aerial for my sat nav now is just stuffed under the air conditioning unit again with absolutely no problems.
 
Thanks. I've got the snooper indago and it sometimes has problems getting a fix, other times not. I guess it just doesn't get used that often.
 
I have a TomTom Classic (original version) with the latest updates & don't use an aerial. It works fine in my Leon Stylance - hardly any delay when I turn it on.
 
My tomtom one works fine but for some reason takes longer to get a fix compared to my last car