Mobile Safari not using GPS / "response.location is undefined" in Firefox 3.5.5

Hello,

I've been using the *navigator.geolocation.watchPosition()* method for
nearly two months now and it has worked perfectly on both 2nd and 3ed
generation iPods with the latest firmware.

A few days ago, however, my iPod's Mobile Safari browser pretty much stopped
using GPS to geolocate and is instead using the IP address which is grossly
inaccurate.  Basically, the first few success callbacks return an accurate
GPS location and then, for some reason, it begins geolocating with the IP
address.  Again, up until a few days ago everything was working perfectly
and all the locations were very accurate GPS coordinates.

Additionally, when I try to use the *navigator.geolocation.watchPosition()*or
*navigator.geolocation.getCurrentPosition()* methods in Firefox 3.5.5 on my
Windows machine, I receive the following error in Firebug:

*response.location is undefined
            var newLocation = new
WifiGeoPositionObject(response.location.latitude, \n
(NetworkGeolocationProvider
line 232) *
What has changed in the past few days and what do I need to learn in order
to continue geolocating in the manner I was doing before?  Everything worked
so beautifully and I'm hopeful it will again.

Thanks,
Nikola