System is Python 2.3.3 on Solaris 9. 

I'm using the classic Python thread model. Main thread puts stuff into
a Queue.Queue() and worker threads get stuff out of it and do their 
thing.

On occaision, I get an exception in the main thread when it tries to
put something into the Queue.

   File "/usr/local/bin/poller.py", line 47, in fragnap_it
     work_queue.put((foo, bar, baz))
   File "/usr/local/lib/python2.3/Queue.py", line 106, in put
     self.fsema.release()
   thread.error: release unlocked lock

This error still happens intermittently, and I haven't been able to 
reduce it to a simple case. I can alter my applications to do 
something useful for debugging this problem when it happens, if you 
can figure out what "something useful" would be. Just let me know.

The queue is unbounded, and I'm using blocking get/put.

The main thread creates 20 worker threads, and 1 recorder thread. 
Then it puts upto 1500 items in the Queue.Queue named 
work_queue. The 20 worker threads take stuff out work_queue, 
process some using pure python code, or others by using 
subprocess.py. Results from the workers are put into another 
Queue.Queue named results_queue. The Recorder thread gets from 
the results_queue and writes stuff to a MySQL db. I've never seen the 
error happen when putting into the results_queue, only from the main 
thread putting into the work_queue.

Thread defines in my python config.h are:

#define HAVE_PTHREAD_H 1
#define HAVE_PTHREAD_SIGMASK 1
#define HAVE_THREAD_H 1
#define PTHREAD_SYSTEM_SCHED_SUPPORTED 1
#define SIZEOF_PTHREAD_T 4
#define WITH_THREAD 1

And all the thread related python tests (test_thread, test_threading, 
and test_queue) pass.