There is a bug in the latest Zune firmware that causes it to not switch tracks when it finishes playing an AAC file (m4a, more easily known as the file type iTunes defaults to). It will still increment the position timer, even though the “time remaining” timer is at zero. There is another bug whereupon the Zune freezes at random while playing music. (I don’t know whether this one is isolated to AAC files, but I have a feeling it is.) Mind you, Microsoft has stated that Zunes can natively play AAC files since they’ve been released.

These issues aren’t isolated to me, as the Zune.net forum regarding non-HD Zunes has a few topics about problems with the latest firmware. The prior firmware was fine, but they added this update so that the new software could sync to the Zune.

I also read that Microsoft is shortly pulling support for all first- and second-generation Zunes, in favor of the Zune HD. I don’t want to up and sell my Zune and look for another mp3 player, but I don’t want to own and commonly use another unsupported device. (For context, my prior mp3 player was an iriver H10 20GB, which was unsupported before I got it. I didn’t want an iPod, and for the record, I still don’t.)