For the past 6 months, I've noticed rust colored spots on our clothing after washing a load of laundry. The spots/stains on our wet clothes cannot be removed by bleach, stain remover etc., as I've tried already. Also, this does not occur everytime we do a load, maybe 1 out of 5 loads we will notice these "rust spots". Is it an oil leak or some type of chemical? If it were rust, the bleach would remove it. What should I do?