M2Crypto bug when using SSL in concurrent server

I've written a simple SSL server using MCrypto. The server is by
nature multi-threaded.

Unfortunately, when multiple clients connect to the server
simultaneously, there's a serious probability that the server will
hang. The hang is always in the same place:

  File "./svr.py", line 401, in do_POST
    data = self.rfile.read(size)
  File "/usr/local/lib/python2.3/site-packages/M2Crypto/BIO.py", line
58, in read
    return m2.bio_read(self.bio, size)

(the first stack frame is my code).

Platform info:

Python 2.3.4

M2Crypto 0.12 or 0.13.1 (both have the problem)

Red Hat Linux (9 or Enterprise 3); different versions have the bug, e.g.

Linux nitrogen 2.4.20-30.9 #1 Wed Feb 4 20:44:26 EST 2004 i686 i686
i386 GNU/Linux

Linux guido.esi.elementalsecurity.com 2.4.21-20.ELsmp #1 SMP Wed Aug
18 20:46:40 EDT 2004 i686 i686 i386 GNU/Linux

Any help?

This is the first time I've written an SSL server using M2Crypto; I've
written several clients and they work fine, even with heavy
concurrency.

--
--Guido van Rossum (home page: http://www.python.org/~guido/)