I'm sorry the cleaning didn't help. Did you clean the moving parts as well as the case? Lint builds up on those to. I ended up cleaning mine yesterday after reading your post and boy did it need it.
This is a neat little tool I use to get into those difficult spots on my machines when I need to oil them. My husband got me one from his job but you can buy them and they make oiling a cinch. Some if you look around do have a longer tip.
http://www.amazon.com/PIN-POINT-PREC...7052726&sr=8-3