Lego Indiana Jones Temple of Doom Battle of the Bridge Boss Battle help?

Same problem - I sit there and fight the Thugee guys for 20 minutes, but none of them drop swords! The only ones with weapons are at the bridge exits and they drop the crossbows only. What's the deal here? I tried fighting only on the bridge and only at the exits, but still no one drops a sword. I'm obviously doing something wrong, I sympathize with the original poster. Ugh.