|Before anything else, I would be curious to know what fabric your diapers are made of! Some people have had problem with premature wear with bamboo diapers. At first glance, your routine doesn't seem off; I don't know your detergent, so I don't know if it's too much or too little, but that should only have an incidence on build-up, not on wear and tear. Drying in the drier is harsher on diapers, but they shouldn't be worn out after 17 months of that I would think!
Have you used any other additive? Bleach, Oxygen bleach, borax, etc.? Have you boiled your diapers or done anything else to them?
ME guarantees their diaper for taking one child from birth to potty-training, so if you haven't done anything weird to them that would void the warranty, you may want to contact them and see if they can do anything about your situation.