Hi,
I solved this issue, but I don't know if is the best way to do.
I think that the problem was that the vendor info don't put in the POST data (in the administrator zone, yes).
I solved this simply put this lines at the end of the template (.../user/edit_address.php), just before "echo JHTML::_('form.token');"
foreach ($this->vendor as $vendorPropiedad=>$vendorValor) {
echo '<input type="hidden" name="'.$vendorPropiedad.'" value="'.$vendorValor.'" />';
}
In this way, all the vendor info is put in the form and then is treated correctly (by POST).
If anyone try it, the test results are welcome.
Regards