Leavewhenempty=yes not working in Asterisk 1.0.9

In my queues.conf on Asterisk 1.0.9, I have set leavewhenempty=yes, but when I tested this yesterday, my test call first rang to the agent that I purposely had not answer the call so that the agent would be auto-logged out, and then when the agent was logged out automatically, leaving no agents in the queue, the call remained in the queue anyway, rather than “leaving when empty” as specified. Am I misunderstanding the function of leavewhenempty=yes? I see no patches or mantion of this in the bug tracker. Would I be helped by upgrading to an 1.2.x version? Please help!

Why does leavewhenempty=yes NOT cause callers that are already in queue to be sent to the next step in the dialplan after the queue, or to be otherwise removed from a queue?