If you google "Luxos U problems" you'll find plenty of references. There are several threads I've seen (and participated in) - Aushiker links to a few, BNA has a thread and there's been discussion of the Luxos in the UK (YACF perhaps?) and plenty in Germany (apparently).
The Luxos - both U and B models - is bit of a lottery. Some people have had no problems, but a significant number of users, such as myself, have had complete failures. Some riders in the US reported failure after rain, but mine simply didn't work from the off.
I don't know how Peter White got those beam pics but they bore no relation to what I saw. I should point out that I commute daily all year round and I've been using StVZO compliant bike lights, including Busch & Muller lights, for the last 6 years and I currently have a Philips LED (what they call the Saferide in the US), a Trelock LS950, a B&M Ixon IQ and an Ilumenox Vega 6 Volt Dynamo Headlight, so I know what the Luxos should've looked like. I bought the Illumenox to replace the Luxos, since it seemed silly to have the dynamo wheel on the bike but no light attached to it. The Illumenox only claims 35 lux (half what B&M claim for the Luxos) but in practice it's just as bright as the Luxos was - which really doesn't say much for the Luxos. At 70 lux the Luxos should have been similar to the Philips, which is an extremely bright light with a wide spread beam, but it was nowhere near it (MTBR has a test and beam shots of the Philips, and my review of the light is around the internet if you're interested). The main reason to buy the Luxos was the (reputed) wide beam but mine was so dim it barely lit the road in front of my wheel, let alone the sides of the road. The one light I am hearing good things about is the Exposure Revo, which is reputedly every bit as bright as it is claimed to be. One of the guys on the BNA thread had had a Supernova E3 but it failed after a year (well, it was apparently after 15000ks but even so ...), so that's yet another light off my list!