With my first, that happened to us, too. I simply would not use disposables again after that. It seemed to happen with nearly every brand of disposables we tried, with some being worse than others, but strange things happening with every one of them, and no definite data about what happens to their reproductive organs with all those strange things next to their skins for such a long time when they are developing so much and so fast?
So, we switched to cloth. We like the Mother-ease cloth diapers, the one-size (www.mother-ease.com). I am now using them on my 4th little one, and find diaper rashes an easy thing to deal with. When we used disposables, the children would nearly constantly have a diaper rash and issues from the diapers. With cloth, the rashes, when they get them, are short-lived.