RDS broadcast is by individual stations, not by region. RDS can be broadcast by any station that has an RDS transmitter, and it is the choice of each station whether or not to broadcast it.
Zippy's post is a reasonable explanation. The station might be broadcasting blank RDS text. Did you try turning RDS off?
The reason why I am suggesting this is I live on the " edge" of where i can pick up a few stations info...and sometimes some weird caracters pop up...and will stay there, or an old song title, and be stuck there till I change a station, or get to the top of the next hill, where I can get the info again....
Will take 2 seconds to try...nothing to loose....
If it doesn't work...you can reprogram the button...remember a few similar threads...reprogramming the button seemed to work also...
