I wondered the same thing, THX. It's obvious that they must be disarmed, but it seems like the Jedi should be able to handle some alien dudes without their sabers. That being said, it seems like a lot of the characters in Star Wars seem unwilling to take risks that could get them killed. I'm sure Obi-Wan tells Anakin that they should sort of "go with it" and wait and see what happens. I don't know if I'm right here, but couldn't the Jedi technically just use the Force to get the cuffs off right away? The other possibility is that some Sith kicked their ass to put them in that position. It's possible that the "Good Job" scene occurs after Obi-Wan is imprisoned by Dooku, so maybe someone on that planet just overpowered the Jedi.