Firefox 6.0.1 doen't obey: If the user denies permission, the errorCallback (if present) must be invoked with code PERMISSION_DENIED.

in: http://dev.w3.org/geo/api/test-suite/t.html?00001

if you chose in the browser "Esta vez no" ("Not this time" I supposse) you
never receive a notification of an error, or anithing.

its bokening 2 recommendations:
If the user denies permission, the errorCallback (if present) must be
invoked with code PERMISSION_DENIED.
The timeout attribute denotes the maximum length of time (expressed in
milliseconds) that is allowed to pass from the call to getCurrentPosition()
or watchPosition() until the corresponding successCallback is invoked. If
the implementation is unable to successfully acquire a new Position before
the given timeout elapses, and no other errors have occurred in this
interval, then the corresponding errorCallback must be invoked with a
PositionError object whose code attribute is set to TIMEOUT.

tested on:
Firefox 6.0.1 for Ubuntu Cnonical 1.0, channel estable.
Kubuntu

I was trying that in my website, using timeout property of the method and is
the same,

if(navigator.geolocation) {
        var geocoder;
        geocoder = new google.maps.Geocoder();
        navigator.geolocation.getCurrentPosition(function(position) {
                        var pos = new
google.maps.LatLng(position.coords.latitude,position.coords.longitude);
                        geocoder.geocode({'latLng': pos}, function(results,
status) {
                                if (status == google.maps.GeocoderStatus.OK)
{
                                        if (results[1]) {

location.href="destiny....."+parseInt(results[1].address_components[0].short_name.substr(0,2),10);
                                        } else {
                                                noLocalizable();
                                        }
                                } else {
                                        noLocalizable();
                                }
                        });
                }, function() {
                        noLocalizable();
        },{maximumAge:2400000, timeout:10000});
} else {
        noLocalizable();
}

function noLocalizable() {
        location.href="default destiny";
}