The devs patched the Run while crouching bug that let you crouch and sprint at the same time and still gain all the buffs. They also made it so you cant sprint then instantly go into crouch. If you have any crouch problems this is why. The fix wasnt in the patch notes, but I can confirm it since I sent the bug in a week ago and now it doesnt work.
EDIT: Stop raging at bioware jeese.