Bald BrickI was looking why Opera no longer will play YouTube clips, and searched forum and came across this thread. the last bit about the
.macromedia.sav suddenly showing up. I am wondering if this is one of those, 'safety' measures when you upgrade an application that the existing settings get saved for you to recover easily your custom settings.
As an example one could early loose
kde4 settings when updating (and sort of without thinking about this until the damage was done)

Because of the .old can be used by others I have taken to add
.my-initials (slight gnome problem here), or
.my-frist-name those two is unlikely to be used by any upgrade program.