For the past two months I've been having problems with my 60GB iPod 5G randomly reseting itself. I use audio files encoded and tagged by iTunes in the m4a format at 128kbps which is apparently optimal for the player (according to Apple). I've gone through every tip and restore suggested by support and other people on these discussions. Nothing has resulted in any improvements. Apple themselves have not been able to give me any help, except to say that nothing is wrong with the player. I have restored to the original settings, done a format, firmware update, and freshly transferred my songs from iTunes. Currently I'm running firmware v1.1.1.
I did, however, find one Mac user (as I am a PC user) that had the same problem and was able to fix his problem by using disk warrior. Since Mac formatted iPods use HFS, and Windows formatted iPods use fat32 there's a bit of a difference.
By setting enable disk usage on my player, the drive shows up as an available hard drive. You can then use Disk Defragmenter on it. Defragmenter will not damage your iPod hard disk because during a defrag it simply reorganizes the physical data on the hard disk so that it is in continuous order.
The interesting thing is after a fresh disk restore, format, and then a transfer of all my songs via iTunes. There were several fragmented files and folders. This suggests that there must be something wrong with the transfer logic for some of the latest iPod service updates.
After running defragmenter on my iPod, I no longer get random resets/reboots, and the actual iPod software runs smoother (fewer jerky transition).
Built Intel P4 640 Windows XP Pro Computer engineer currently working as a software engineer...