Today while on a ride with some friends who have just started taking up mountain biking, I snapped a sideplate on one of my links. I think it happened when I went cross-geared for a tad while trying to dump my front to the inner and kick my rear to the large cog in order to power my way through some sand. Anyways, the chain got sucked up and I lost momentum. Whether the broken sideplate caused the binding and resulting chainsuck or was the victim of the chainsuck because I was radically moving the chainline under load and vibration, I can't tell but for the rest of the ride, my shifting was horrible and the chain was skipping around.
I somehow got it into my head that the rear derailleur was misadjusted due to cable stretch or something and was playing with the barrel adjusters to no avail. It wasn't until we all got back to the parking lot that one of my friends noticed the sideplate of one link hanging loose and the other sideplate bent. I hope I didn't damage my drivetrain by riding what I estimate was about two hours with a faulty chain. I'm taking it into the LBS for a new chain and an inspection. BTW, the chain is a CN-7700 which is the same chain originally made for the Dura-Ace road group. This is also the standard spec chain for XTR which is what I have. I'm not sure if it being designed for a road group has anything to do with its durability but I've been reading a LOT of reviews about people snapping the 7700 in offroad situations.