Why does my widescreen TV only switch during BBC regional programs?
When a channel broadcast in widescreen, this widescreen picture actually has the same resolution as the 4:3 picture, except the "pixels" are wider.
A widescreen TV needs to understand the difference between the two otherwise identical TV pictures, and can do this in two ways:
1. When connected via a SCART connection, there is a "widescreen" connection on the cable.
2. By sending a special signal on line 23 of the TV picture.
The Digibox only generates the first signal, so normally you only get the auto-widescreen signal to the SCART connected TVs.
However, the BBC regional programmes broadcast BOTH signals (the second as part of the TV picture), and as your LCD TV can understand this signal, it will switch to widescreen.