Recently I noticed that my WIP marks the cell "0,0" as edited - although I didn't add anything (and there aren't any new items on the object list) there and there is no chance I could modify it by accident. Even after cleaning the file in Enchanted Editor the cell gets marked as soon as I open the .esp in the CS. Anyone knows, what could be the reason and how to fix it? And before anyone asks - the only copy of the file I seem to have is from a much older version, so going back is the last thing I'd want to do...

Thanks in advance!

well known CS glitchesYou can get it fixed until resaved from CS.
automatic:
tes3cmd.exe clean --replace --hide-backups mymod.esp, and TESTool clean esp.

Or what you are doing already, from Enchanted Editor
Or, from the CS file\data files\details if you want to hand pick cells, press delete key to toggle ignore change on load, load, save immediately (not entirely sure it works for 0,0 though)
[EDIT]clarification

Ah, so there is no permanent solution? Good to know - thanks for the answer!