All of the channels which i had stored have now de-tuned themselves, seems like the stereo mode has changed (on its own!). Everything on the remote works, except for the tuning button. It doesnt seem to be a problem with the remote, as the tuning button will still call up the text menu when pressed with text on.
Is there some sort of a manual reset on the tv i can try? I *think* i know how to fix the problem with the channels, but need to get into the tuning menu to start with!

Ross Morcom, October 2005

Problem solved - the TV had somehow switched to hotel mode, while at the same time de-tuning itself. Not sure how that could have happened, but sorted all the same.
For reference, hotel mode is switched on/off using the service menu. To get to it, turn the TV on whilst holding down the i button on the remote.
Again for reference, and to make this more easily found in searches, the chassis number for the st 63-725/8 is cuc6330.

Ross, October 2005