dude...had the same prob..but i figured it out
it's the freakin windows media that keeps the file "running" does the same thing in xp
just soft reset your device "lil button pressed with stylus RIGHT UNDER the record button...
that simple
then
locate the file in file explorer..
and kill it dead
(tap and hold and tap delete)
soft reset just eliminates the power getting to the inner components or what ever and kills lock ups... and ...deletes mp3s lol...
