AirCard 810: manual network selection mode not working

If you login to the configuration website via http://netgear.aircard and there try to manually select a network, you cannot save your selection. The attempt is denied with "Error saving changes". Hence, this feature is not working, you are limited to "automatic network selection mode", which can be very problematic if you live in a border area and frequently end up in a roaming network.

How could this error be reported to Netgear so they could fix it in a new firmware?