I’ve never been able to get Google Music working in Firefox. Ironically, IE was the only browser that I could get it to work in. I could log in, see all my music but whenever I clicked on a song to play, I would get “Oops, we have a technical issue:Please refresh this page in your browser to get back to listening to your music. If issues persist, make sure you have Flash enabled and working.” Naturally I am already at the latest version of flash and clearing the cache etc didn’t work. I searched this afternoon and came across this thread which recommended adding music.google.com to the flashblock whitelist and sure enough it worked. Thanks to JackieGleason who posted the question on their linux box, fixed it themselves and then posted the solution.