Do the size 5s still work? If so, then you probably got a bad batch and I would call the number on the Huggies package and complain. They will probably send you a coupon for a free package or at least a discount on your next purchase. If you're having the same problem with the size 5s, then it's probably not a defect.
I have to say that I feel for you 'cause I hate those crystal thingies!! That's such a mess. I never had problems with those until I got a "bad" batch of pullups and the velcro would cause a small rip in the inner lining and when we'd go to change it, there would be those crystals everywhere!
Anyway, we've always had the best luck with the Kirkland brand diapers from Costco, even at night. I still have a partially used package of the Huggies Overnights that we never used 'cause they didn't seem to do any better than the Kirkland diapers and were much bulkier. My son is finally potty training so we're using the pull-ups now. He's 3 1/2 and is trying really hard to potty like a big boy. We've been ready for him to be potty trained for a year or more, but it took a while for him to get there too. It will happen. Sometimes it's just on their time schedule instead of ours. :-)