UPDATE: And this morning it works again! Amazing. Yesterday I tried everything together with the support guy on the phone - unplugged power, hard drive, network, everything - but it was RROD still after 8-10 retries. And now, 20 hours later it works again? Weird. I'll let the box run for a few hours today and tomorrow. If nothing crashes I'll call Xbox support again and hear what they've got to say about it.
ANOTHER UPDATE: And a few days later it really, really died so I sent it in for repairs. :) I just got it back today - it took about 2 weeks "door-to-door", which is not too bad considering it travelled to Germany for repairs and back again to Sweden. The motherboard replaced.
Some time ago our Xbox 360 here at home started to glich - the screen froze up after a few minutes with a short squeeky noise from the speakers, one of the red lamps on the front lit and I thought the Xbox was going down. I contacted the support center to have it repaired (I would have to pay for it because we've had it for a couple of years and the warranty didn't cover this error), but they had problems with their incident system for a couple of days and therefore couldn't submit repair request... I asked them to call me back or send me an email when the system worked again, but they couldn't do that (boooh). That made me a bit angry, and I kind of dropped the Xbox from a few inches of height into the floor... and it worked pretty well after that!
...until now that is. This morning we had a real proper RROD (Red Ring of Death) - hardware failure. Argh!
I called the support center again and was prepared to pay for the repairs, but I was told that Microsoft extended the warranty for RROD/hardware failures to 3 years - good! I just got the UPS lables to print out and stick onto the box and will arrange for UPS to pick it up on Monday. They said it might take up to 3 weeks to have the thing repaired and sent back to us, but there's not much I can do about that.
I guess we'll have to power up the old Xbox console now and play Worms for a while :)