We have recently been testing out our OS stash now that LO has gotten big enough. I have mostly fuzzibunz, and have been struggling with getting the fit correct. However, I've also noticed the few times she's worn them that her entire diaper covered area gets red. This does not happen in the other brand pockets we have (Kawaii, BumGenius, Happy Heiny). Is it possible that she's allergic to the material in the fuzzibunz? I bought them used, but they have been washed in our detergent, so I don't think that would be the problem.
Anything else I should try, or is it maybe time to sell the fuzzibunz and get a different brand?
BFP #2 - MC Aug 2012 - D&C w/ complications

Re: Allergy?
The inner of Fuzzibunz should be the same as most Kawaii and Happy Heiny, so I don't think the material is the problem. However, since you bought them used, the person before you could have easily used a product (a certain detergent, cream, additive) that is irritating your baby.
Your detergent alone may not get all the build-up out, if that is the problem. I would do a whole bunch of hot rinses (with a squirt of blue dawn if you want) and see if that solves your issue.
BFP #2 - MC Aug 2012 - D&C w/ complications