Very interesting, I use O2 and have exactly the same problem only with BBC radio channels. My dealer has taken logs and did take my BM 5 away for investigation. His tech guy managed to reproduce the issue in the showroom and did a full software reset of the BM5 which seemed to resolve the issue.
It worked for a week or so when he delivered it back but then the issue came back!!
B&O in denmark have suggested that they change out my hard drive so that they can investigate the issue on my drive although not sure what they will learn from this.
As I mainly listen to BBC stations it is rendering the N.Radio feature useless
Will keep you updated as the issue progresses
Cheers
Steve