After testing, it seems that Internet Radio option under firmware 3.0.4 on both 500X and 400X gives service unavailable.
It looks like Shoutcast changed something on their servers that is affecting this functionality on 3.0.4.
Mede8er is aware of this issue and looking into a fix for 3.0.4
It is also noticed that V4beta5 is not affected by this change. Internet Radio on this version is still working.
So you might consider to upgrade to V4beta5 if you don't want to wait for the Internet Radio fix for 3.0.4
regards,
Maasbommel
Update:
Issue is fixed with version 3.0.5. Also in 4.0.4
