Yet another - mine is a 28pw6006/05, and has developed the "auto switch off" failure problem after 18 months, although it did it randomly a handful of times earlier on. Our local engineer says that the controls chip does not have adequate heat dissipation, and suffers all kinds of failures, (channel switching, lack of video controls, switching off...) when it overheats. Eventually the heat damages it permanently. Philips has apparently been aware of this for some time, and eventually changed the design, but has not publicly acknowledged it - otherwise I would expect to see it on the product FAQ on their website!! I have emailed their customer services, sent the engineer's report and proof of purchase, but have not yet heard anything back from them. Watch this space.
Tony Fisk, May 2005