Since returning from abroad I haven't been able to get a signal at all.
I recently upgraded my phone, and the signal strength seems to have dropped!
I was abroad last week (Italy), and it took two days before I received the "Welcome to Italy" message. Since I returned on 18th, I haven't received any text message about being back in England, and haven't been able to get a signal at all at various places between Edinburgh airport and St Andrews.
Re: Since returning from abroad I haven't been able to get a signal at all.
I'd restarted it several times.
I tried manual searching, as suggested, and it was showing all networks as "forbidden", but it still let me select Virgin, and it seems to be working now, although signal strength is still not as good as it was with the old phone!