I got home today, fired up the xbox so I could play some CoD:WaW for 30 mins before eating. Much to my surprise, the screen is scrambled in the manner of a PC when you set the refresh rate or resolution over what the monitor can support. First thing I do is flick the cable to TV mode to check it hadn't somehow got messed up. I have a look to see if it will support 1080i (no luck) and then 720p (no luck either), all I get is the mess you can see in this pic here (http://twitpic.com/fcudd). It works fine in 480, just not in any HD mode.

Anyone got any ideas as the official support line is "find another cable" which is a little annoying as I don't have anyone near with one.

Otherwise it's trying to wangle a replacement (for the 2nd time)

I've had that a couple of times. Usually solved by switching the TV off for a few minutes.

Did you get any red lights on the console?

Not in relation to this problem but I had the red lights about 18 months ago

you can buy a new cable from a supermarket for a fiver. Wiggle the existing one around a bit, mine goes to 480 sometimes when it's not seated properly.

Yup very likely cable is not seated correctly.