autosave is an engine feature,which means its almost like its own program built within a program,what autosave does is check a few things first to make sure saving can be done in a safe manner.
"checks to make sure playback is stopped(as jb said)no midi/data is being transfered,exc.
its runs the engine everytime you hit stop.
i notice it even in newer projects,not to the point it interupts flow.
is it interupting flow in anyway?
have you tried shutting it off to see if this is indeed what your seeing ?
matter of fact what are you seeing and not sure i understand what the problem is?