I use Daz or Ariel and I also have white marks on my clothes sometimes on a dark wash... I do NOT think it's your washing maching as I've had 5 different makes of machines in the last 18 years! I think that some powders don't dissolve properly causing the white marks, liquid versions don't leave white marks! I'm not sure about your stains not coming out, maybe you're overloading the machine? or maybe they just need a stain treatment before washing? I use oxi for stubborn stains before I put them in the main wash.