One of the things I've done with my spare time is learn more about regulators and what causes the dreaded regulator creep. I now understand the cause and can hopefully fix it if it happens to you (regardless of where you got your reg).
Most people I've spoken to and most things I've read online have stated that it has something to do with the diaphragm in the body. Unfortunately that is not the case. If your diaphragm is not sealing then you lose pressure. No matter how high you set the regulator, the low-pressure gauge will continue to drop.
Creep is cause by a faulty seal on the regulator seat capsule (number 10 here: http://www.micromatic.com/sites/5/images/schemas/13.png" onclick="window.open(this.href);return false;). You can easily remove this and replace the o-ring, or in cases where it is threaded into the body, lock-tite or similar solves the issue.
So if you want to have your reg looked at and hopefully fixed, just bring it by sometime
