I too am having issues with IE11 on both Windows Phone and Windows 8.1 x64 in that every time you go to a page you get the progress indicator and the page does not refresh. To get around this you have to (Ctrl)F5. It works perfectly ok in Firefox.
I have also tried adding BBC Radio 2 URL
http://www.bbc.co.uk/radio/listen/live/r2_aaclca.pls but this does not work but the Dirble radio links work ok.
I love the work you have done on this and I am looking forward to the next version.
One thing I am not keen on is the blue message boxes that appear when you do anything, they obscure other things especially on Windows Phone.
I would also like to see just a play option rather than add to playlist
EDIT
I cant put my finger on it but there seems to be a problem using WiFi on my Pi, I have a WiPi USB dongle which I can use to connect to RuneAudio but when I add anything from the library to play I am not getting any sound.
Keep up the great work and thanks
http://pastebin.com/8Lrmdzvv