Developer has not responded to support forum posts in 9 months as of this writing. (Though last spring he responded to my inquiries via his web site and was helpful.)
In Opera (on the Mac), the playlist player doesn't display the track names - the list is all collapsed up into a tiny bottom border. I found this to be true last spring, not just with the WordPress 3.5 update.
It's very frustrating when developers abandon plugins, and even worse when they don't take the courtesy to inform users of that. Obviously a lot of work went into this plugin; the admin panel has a good number of options, making it one of the better WordPress audio plugins I've seen, feature-wise. But none of that matters if the plugin isn't updated.
(Personally, I never liked the GUI much, but that didn't affect my rating; a friend helped me add a custom interface that looked much different from the default.)