IPod nano 7th Gen. occasionally reboots

Question

I've bought myself an iPod nano 7th Gen. about two weeks ago. I updated the firmware to 1.0.2 and synched some playlists on it. During the first two days my iPod nano shut down and rebooted itself about 10 times, no exaggeration. I went to my Apple Premium Reseller, turned it in and got a new one a few days later. I'm using that one for about a week now and I still got the same problems:
It happens when I wake the display up and music is playing. I hit the lock button, the music stops, the screen turns on and shows the Apple logo and then a few moments later the greyed-out homescreen with a spinner. Sometimes it shows the home screen directly and a spinner when I tap on the Music "app".
In some occasions I first hit the home button, the music kept playing and the screen stayed off, then I hit the lock button and my iPod reacted as described above.
Since two days, I observe another error which occurs often when editing a playlist or creating a new one, but also on wake up like above: The music stops, for about half a second a weird sound plays over the earbuds and then the iPod shuts down and I have to manually turn it on again (tap and hold on lock button).
I'm writing this now because I listened to music the whole day today and nearly everytime I took the iPod out of my pocket it rebooted like described above. I suspect that this is a software problem, so please, Apple, do something! These bugs make it really annoying for me to use my nano for what an iPod is for: listening to music.
Some further information: In iTunes, I checked the "Convert higher bitrate songs to 128 kbps AAC" option and filled the iPod nano with about 12 GB of music. I listen to music only with the Apple earbuds, no bluetooth headsets or car dock stations. For selecting songs, I mainly use playlists.

Answer 1

Okay, I tried unchecking "Convert higher bitrate songs to 128 kbps AAC" and this seems to solve the problem. Of course this is not satisfying because I can't fit all of my music on it anymore; but at least I can listen to it.
I still hope that someone at Apple reads this and tells me how to really fix that. For me, this experience is like buying a car that breaks down every 500 meters. An iPod nano that can't play back music without interruption is embarrassing!