Bit of a strange one.

I have a new Sanyo 26" Freeview enabled TV (from the Warehouse) which keeps resetting the channel numbers from the friendly numbers to the digital RF numbers (eg 802 806 etc). E.g. rather than the 1, 2, 3 etc we are used to.

Rescanning seems to correct the problem, but it doesn't seem to stick for more than a day or so.

My research indicates that the broadcaster sends some data to map the friendly channel numbers for Digital and I was wondering whether a less than optimum signal might cause this part of the signal to drop and the TV to reset (or loose) the mappings to the friendly channels.

Is this likely or something completely different?  Should I be taking the TV back or checking other things first?  The signal strength is mediocre - but the stations all play without pixelation.  We have 2 other (different sizes) Sanyo TVs and no problems like this before.