Also my experience, just now. Ugh.
Easy unlocked, and checked my difficulty under chapter select, and the rest should've popped.what
On chapter select, hit X and there'll be little yellow icon flashing beneath the difficulties to show you which difficulty you complete that particular chapter on. Unfortunately, it's very easy to bump the difficulty when you're quickly restarting from checkpoint...
Last edited by Kievah; 05-23-2013 at 04:58 AM.