I have had the same experience - I too, bought in bulk when I see the jumbo boxes but have found that the nappies ALWAYS burst overnight with the delightful gel & contents going everywhere! I was contemplating switching from Pampers altogether until I spoke with another parent who recommended the Active Fit nappies instead. However, I NEVER had a problem with exploding nappies until I started buying the special offer boxes. I have switched to Active Fit now and they no longer explode but I don't get them in the boxes. So, I do think that they use inferior quality nappies in the boxes.