I bought these crocs for my 7 year old son.  Crocs are extremely convenient for summertime use, as they slip on and off very easily.  Unfortunately, these pair have a slightly different heel strap than past crocs, and I noticed my son pulling it more to fit his foot into the croc.  The end result was that one of the 'rivets' that holds the heel strap in place came out.  While we were unable to locate part of the rivet at the time it became displaced, I was pleased that a local Croc store was kind enough to give us a replacement rivet free of charge.  In talking to the store clerk, it sounded as though this is a regular occurrence with this style.  Since replacing the rivet, we have had no additional problems.  Hopefully, it continues to remain in place, and does not decide to pop out an inopportune time.