[cbhl]

The bottom of the encoder is supposed to be covered with a sticky adhesive (kind of like a label) and is covered with a piece of plastic-coated paper, if I recall correctly. Make sure you remember to remove the paper and stick the encoder onto the motor properly (as per the instructions).

Also, be careful with those encoder cables -- they're delicate. We managed to pull one of the ends off of one of ours -- so we can't use it any more. (We don't have the budget to buy another one and have it shipped all the way up here, anymore, either...)