|The times that I've had huge stink problems have been with Tide (combined with my in-laws' horrid water). I would wonder about a baby detergent, as they are often more like soaps than detergents, and therefore a bit more prone to build-up (soap scum) and/or don't do as good a job with getting things clean. They can also contain some fabric softener (though probably not all do).
I know I've read about Oxiclean previously here--have you tried doing a search on the term? I don't know if it will solve build-up problems, but I know that some people use it fairly regularly. I believe that it releases hydrogen peroxide, basically, and I think it has some washing soda in it?
For what it's worth, our worst stink issues were with a top-loader, so it's not just front-loaders. I used a front-loader with store detergent for four years in the UK with no real issues that I didn't bring on myself. Moving back to the US, I've had to figure things out all over again. I have no idea why these front-loaders should be different. I've finally hit on what seems to be a good arrangement for us: dry pail, pre-wash, sanitary heavy wash with about a teaspoon of Country Save, extra wash (figured it was more effective than an extra rinse). I don't like having to throw in the extra wash, but it seems to be helping, and I wash our other loads on cold as much as possible to assuage my energy conscience.