The tripod head's tilt will not lock in place - can anyone that knows tripods tell me if I'm missing a piece like a rubber washer?
Even when tightened down all the way the tripod still tilts to the front and back when weight is applied.
If you didn't get any solution for your tripod head you can try another one.
Have you tried to unscrew the head and check if is 1/4" screw?
If is 1/4" I recommend this tripod ball head, I bought this a month ago and I'm very happy! It's very solid, good built. Check this out: http://www.ebay.com/itm/200906660145