[Tutor] Unable to catch exception

[James]

All,

I'm having a rather strange problem that I'm hoping someone can shed
some light on. I'm trying to catch a BadStatusLine exception raised by
the httplib library. Below is the traceback that Python gives me when
something goes wrong with one of my programs:

-----

    Traceback (most recent call last):
      File "/usr/lib/python2.5/threading.py", line 486, in __bootstrap_inner
        self.run()
      File "cherryTree.py", line 237, in run
        qDump = browser.open( url ).read() # get the new c3 queue
      File "/usr/lib/python2.5/site-packages/mechanize/_mechanize.py",
line 203, in open
        return self._mech_open(url, data)
      File "/usr/lib/python2.5/site-packages/mechanize/_mechanize.py",
line 229, in _mech_open
        response = UserAgentBase.open(self, request, data)
      File "/usr/lib/python2.5/site-packages/mechanize/_opener.py",
line 181, in open
        response = urlopen(self, req, data)
      File "/usr/lib/python2.5/urllib2.py", line 399, in _open
        '_open', req)
      File "/usr/lib/python2.5/urllib2.py", line 360, in _call_chain
        result = func(*args)
      File "/usr/lib/python2.5/site-packages/mechanize/_http.py", line
700, in http_open
        return self.do_open(httplib.HTTPConnection, req)
      File "/usr/lib/python2.5/site-packages/mechanize/_http.py", line
675, in do_open
        r = h.getresponse()
      File "/usr/lib/python2.5/httplib.py", line 928, in getresponse
        response.begin()
      File "/usr/lib/python2.5/httplib.py", line 385, in begin
        version, status, reason = self._read_status()
      File "/usr/lib/python2.5/httplib.py", line 349, in _read_status
        raise BadStatusLine(line)
    BadStatusLine

-----

This error happens when I try to open a page using mechanize. From
what I gather this error only happens when the web server returns an
unknown error.

The error only happens once every blue moon, but to avoid a crash I
setup a try/catch.

try:
   <download page code here>
catch BadStatusLine:
   print "yuck!"

However, somehow the thread that this code is in still raised a
BadStatusLine exception and the thread stopped cold.

Thoughts on how to possibly fix this?

Thanks!
-j