Problem tuning Thomson 28WX35US in Digital

Apologies if this is in the wrong forum...

A few years ago I purchased a Thomson 28WX35US with integrated Digital TV. Originally set up in Reading the aerial in the flat I rented wasn't suitable and it would only receive 2 channels, however since moving to Portsmouth, I have a new aerial and expect it to work...

However it doesn't. When trying to perform auto tune the scan finds no signals. However when running the test it completes okay, and displays BBC News 24 on digital in the background.

Thomson suggest that the tuner is broken and that I should return to have repaired, however from the test I would assume otherwise. It is as if when trying to auto tune it is looking in the wrong place (maybe the old transmitter).

Does anyone have any suggestions before I have to lug it to a repair agent?

Thanks