I've got a red sex-link about 1 1/2 yr old. She was laying great up untill about 3 weeks ago. Now every egg she lays 1/2 of it is good hard shell, the other half is just paper thin and will break with the slightest pressure. Its always the small end of the egg that is paper thin. She has oyster shell there 24/7. Has anyone eles had this problem?