I had this happen last night, created an account in fact to report it if I could get it to repeat but I couldn't. Anyway my broker, who is also my expedition leader and manager just sat around with no job after the liaison meeting was done. The way I finally got him to go to the depot was reassigning the manager position.
For a play by play if you're interested, the first thing I did was remove masonry and tell him to stop what he was doing, at which point he decided to manage work orders. I then cleared all work orders and tried to stop him but in the end he canceled because he wanted a drink(or I drafted then he wanted a drink can't recall which anymore). He emptied the barrel and then decided to put it away, after which he went to meet with the liaison, which I did nothing to stop. After finishing he went to idle in his bedroom and I waited for a awhile trying a few things at the depot like changing who can trade temporarily to see if that would start him. After that I drafted him, stationed him next to the depot, then locked his bedroom door and deactivated him, all in hopes he would stay put at the depot and then realize he had work to do, since the depot was placed in a designated meeting area, but he chose instead to try and return to his room and stopped half way, guess he realized the door was locked at that point. After hunting the forums for any odd behavior about the broker, I decided to just try reassigning the manager position, at which point he finally went to the depot to trade.
My attempt at seeing if I could repeat it had him cancel for a drink off the manage work orders, managed to forgot to clear that before the traders arrived, he then went straight to trade at depot after he finished drinking. Main differences this time was he didn't empty the barrel and I didn't try to draft him to stop anything. Oh and if you're still reading sorry about the long winded post I never seem able to shorten these things and hence one reason I don't usually post much on boards.
Edit: Forgot to mention this was with 33d on a save from 33b.
[ December 02, 2007: Message edited by: Razordw ]