Yes, there is an issue with the current sandbox. I've tried out a new one and it seems to be working:
sandbox_pattern = https?://(www\.)?amazon\.(com|fr|de|co\.uk)/(ap/signin.*|gp/dmusic/.*|gp/redirect)|https?://.*ssl-images-amazon\..*|file:///.*/amazon/home.html
Additionally, Flash must be enabled in order to stream Prime music.
Yes, there is an issue with the current sandbox. I've tried out a new one and it seems to be working:
sandbox_pattern = https?: //(www\ .)?amazon\ .(com|fr| de|co\. uk)/(ap/ signin. *|gp/dmusic/ .*|gp/redirect) |https? ://.*ssl- images- amazon\ ..*|file: ///.*/amazon/ home.html
Additionally, Flash must be enabled in order to stream Prime music.