I've seldom used threads, but here is a suggestion to simplify things. I see no reason to have a central worker thread in the scenario you are presenting. It looks like the only thing you are doing is handling multiple requests individually. Socket accept works in a round robin fashion that works well in a mutli thread/process environment. Create your socket and then create threads/forks, have all of them do a while($sock->accept()) and you are good to go, don't complicate things with queues and threading unless you really need it. Even if you keep the threading for some reason, I'd still suggest handling the socket this way. It'll simplify your code and probably clear up your issues which most likely are caused by some sort of unresolved race condition.

I'd look at Net::Server, not only will it hide a lot of code and prevent you from re-inventing the wheel, it even has a mechanism for handling a listen port and log4perl it seems. Might save you a lot of headaches.

Edit Net::Server also can do useful things like have a min/max connection pool that grows your processes dynamically