All of the BBC radio stations are now available on AAC streams (presumably for itunes/apple cusotmers) - and these streams work fine on Nokia Internet Radio.
(I notice the BBC radio 1 streams are now showing in the Internet Radio station directory)
(the Nokia internet radio player needs to be closed, when you first open a PLS file)
To avoid having to download the PLS every time you listen, for convinience, I've packaged them into easy to use/save links from the phone browser: http://honeyball.com/radio