It seems that smplayer is saving settings (equalizer, deinterlacing) for each file: how it does it, and where are they saved?
It is a very good characteristic if you open the file more than once, and something that to my knowledge other players do not have.
However, settings are saved versus the full filename (including disk & folder), so if you move the file,
something that happens more often that expected, even without renaming it the settings are lost!
Could not be better saving the settings versus something more invariant, for example filename-date created, or filename-filesize?