I rebuilt my rear hub this morning - it was disgusting. When I got out to the trails (no, i didn't ride it before I got out there), I hopped on, and as soon as I started pedaling, the right side of the QR got pulled out of the dropout. It should also be noted that I replaced the derailleur hanger this morning. No matter how tight it was, the QR would not hold. I reversed it, and it still pulled out on the right side. Is this likely to be a QR problem? I closed the cam, and then just used pliers to tighten the nut on the other side, and it still wouldn't hold.