I've just bought a Philips 28DW9625 IDTV (yesterday) but it has a very strange problem. We find that, after the set has been switched on for about 1/2 hour then it stops working properly. We first noticed this problem when we installed the set. We were channel hopping and after a while the picture went black. The only way we found to get the set working again is to switch it off and on at the main switch. Later on when we had been watching the same channel for a while, when we tried to change channel nothing happened. We could change the volume, switch the set to standby or activate the setup menu but most other functions did not work. When we changed the set to analogue mode then the picture was screwed up (top at bottom and bottom at top) and the sound was from a different channel. We could change channels but the picture was still wrong. The only way we could fix this is to switch off/on again. Similar problems to this kept appearing throughout the rest of the day. I have checked the obvious - aerial cable, remote batteries, user guide and cannot fix it. I am sure it is not a signal strength problem since we recently had a new wideband aerial and the engineer checked the signal strength of all the digital channels. Is this a known problem? Is there any change of the set being repaired or should I take the set straight back to the shop for a refund? I have already had two faulty sets (not IDTV) and I am tired of all the hassle this has caused (the other sets could not be repaired).