I have, well had, a 2GB second-gen iPod Nano. Now I have a very slim brick.
When I upgraded to iTunes 8, it offered an update for my iPod. I let it do its thing, then resync’ed it. I noticed that the iPod rebooted after the sync — no big deal — but then kept rebooting (back and forth …) forever.
I tried resetting it; nope, it would just start doing its thing again.
I tried putting it into disk mode, then restoring it; nope, back and forth, back and forth …
In desperation, I tried restoring it on a PC, which needed to reformat the iPod. Partial success; it sync’ed music from the PC, but since my working music library is on my iBook, I had to restore and resync, and guess what? back and forth, back and forth …
I’d heard that the problem could be caused by empty podcast folders, so I cleared out and rebuilt my library, put the iPod into disk mode and restored it on a PC, resync’ed on the iBook and … back and forth, back and forth …
As a last try I’m going to fsck it under Linux. I might be stuck using yamipod, which is probably a bonus, as all I use iTunes for is as an iPod conduit. I really miss having a Rockbox-capable player, as it just worked the way I expected.
UPDATE: yeah, that last one did it. Shame about yamipod’s UI.