Q: after syncing play list, menu says no music. Under settings / about.... it shows 25.5 GB used as other. Tried all resets, reloads ect.

I'm having the same issue. It all started after iTunes update to v.10.7. Tried to uninstall and reinstall older version, but now iTunes informs it can't read library (created with newer version) and shuts down.

It could be an indication or a damaged or dying hard drive.  I would recommend doing a disk diagnostic on the iPod's HD using the instructions given by turingtest2 in this older thread.  He also covers what the resulting numbers indicate.

https://discussions.apple.com/thread/3784647?start=0&tstart=0

If necessary, post the resultings numbers and we can verify what the next steps to take.

B-rock

No problems with the hard drive. And after a web search I found several instances of the same complain from iPod Classic owners. The new 10.7 iTunes version is causing the problem. I removed it, reinstalled 10.5 version, realoaded an old library.xml file and the device worked fine again.

I must remember to never allow iPod automatic updates, and always update it just after a complete backup of all my files and library. Unfortunately, I lost many extense playlists in this process, that took me a long time to build. Learned lesson.

It has been a damaged/dying hard drive for some while for others it is newer versions of iTunes.  Glad to hear you figured it out though.

B-rock