I've got one of these locks, as does another person I know. Both of ours have frozen and don't open at the set combination (meaning even if you go through all possible combinations it won't open and your computer is stuck). As well, they will open at incorrect combinations sometimes. The mechanism is difficult to work and prone to problems because of the way the flip-switch on the back of the lock sits. I do not reccommend that anyone use this lock.
I would trust other Kensington locks, perhaps those with keys, but not this one.