I too am having the same problem.
I updated to the most recent beta version and has issues with the thumbnail generation, general slowness so I regressed back to the stable version that was released last year.
when I did that, world radio would no longer load beyound country N.
I then went to the most recent beta version and reloaded world radio with the saved file that I had (unsure of that version but it was not the most recent). it installed properly but when attempting to view by country, or in the case of the US, by state, the radio stations are in the wrong countrys and states. When I attempted to load the most recent version of world radio, I encountered a run/file path error 75 on step 3.
so as of last night, I've uninstalled (deleted) the PMS 3 media server folder. Ran CC registery cleaner and reinstall PS3MS most recent beta version. I have not had a chance to test the reinstall but all of my settings needed to be adjusted so I'm pretty sure I blew out any related files. I will test PS3MS first before attempting a reinstall of world radio.