WMP10 and latest Karma firmware and drivers.
I have just done a new experiment which i'll detail and maybe it'll make sense to you more than me.
1. Turn of encoding and limit my smartlist that is synced to the Karma to 100 tracks.
2. Delete everything on the Karma (using the Karma itself)
3. Sync
4. MC reports 100 files, name tag in place, no other tags.
5. Close MC
6. Karma reports 100 files, all tags in place
7. Run WMP, it reports 100 files, all tags in place.
8. Close WMP, run MC
9. Files start deleting automatically! Can't cancel but i close the dialog and navigate to Karma->All Content.
10. under 100 files reported - but all tags are suddenly there
11. Refresh and refresh until only 5 files are reported - these 5 have the name tag, no artist or track tag, the album tag has the artist in, the file has the track number in.
12. Refresh to find the smartlist files being added again.
13. Ends with 100 tracks reported, still with the 5 bad ones (impossible to delete from MC becuase the file info is wrong)
14. But the Karma itself now reports 105 tracks - each of those bad ones are duplicated.
Seem to be 2 big issues here - 1 is that some track's tags are being corrupted and 2 is that even the ones that aren't corrupted are still being deleted on sync, even though they match MC.
Hope this helps - let me know if you want me to try anything else....