so i got my Leek about four months ago, its just the standard stainless version. i haven't bee abusing it in the least or anything other than just opening packages and cutting small easy things. a week or so ago i noticed that it no longer opened all the way when i pressed the assisted opening stud on the back of the blade, it only comes out about half way and it takes the thumb stud to make it open the rest of the way. i've cleaned it and oiled it and still no go. any ideas? thanks