I have set up presets for, amongst others, the 4 main UK BBC radio stations (1,2,3 & 4)
As far as I can figure it, there is a problem with the presets, I can only get "NO AF information" on any preset, but if I put the tuner on bank B, and tune in, say Radio 2, manually with the AF on, it'll retune faultlessly and the debugger will work fine. Even if you had player on, I would be pretty sure that it re-tuned and would be playing the best frequency when you got to Devon, this way.
I have not been able to replicate the fault of re-tuning to other stations, but I haven't been much out of the immediate area.
I think that there is also a problem with traffic announcements on AF. You will find an extensive thread on this under general.
I'm no expert, but I think Rob is right, that the AF only stores adjacent frequencies. The confusion may arise, because, at the inception of the RDS system, Blaupunkt were offering an alternative where an upgradeable memory card stored all the national frequencies and compared them audibly, re-tuning to the strongest.