Comment 4 for bug 801295

After more experimentation, I don't think this is necessarily a problem with packages or audio backends. I am now able to get both behaviours on the same MP3, with the only pattern being that if an MP3 doesn't allow random access, I can get it back by first playing an MP3 that does, and then jumping to the first MP3 by clicking on it in the play list in the right-hand column.