Here's the best source for Speedtouch firmware:

http://www.speedtouchforum.de/viewtopic.php?t=1089

And the upgrade tool:

http://mirror.opensourcehub.com/pub/speedtouch/utilities/UpgradeWiz/v4.4.2.1/

Yeah, their web UI is not the best for advanced use, but has everything that "normal people" need. I don't use it at all here, of course -- just treating the device as a dumb bridge and using PPPoE on my firewall/server box instead.

Cheers