BotoServerError: 505 HTTP Version Not Supported (iam)

[Fernando Álvarez]

One of our customer is always triggering this exception when trying to create a server certificate. I'm not able to reproduce this issue when I try to add a server certificate, it always success, so I've no idea why is this happening:

Unknown error when creating certificate depjvbvaqpg-1373874233. Exception: {'request_id': None, 'body': '', 'error_code': None, 'error_message': None, 'box_usage': None, 'reason': 'HTTP Version Not Supported', 'status': 505}.
Traceback (most recent call last):
  File "/srv/www/addonssl/web.py", line 136, in _create_certificate
    iam.create(name=iam_key_id, body=cert, private_key=key, chain=chain)
  File "/srv/www/addonssl/iam.py", line 71, in create
    _get_connection().upload_server_cert(_cert(name), body, private_key, chain)
  File "/srv/www/.heroku/venv/lib/python2.7/site-packages/boto/iam/connection.py", line 773, in upload_server_cert
    verb='POST')
  File "/srv/www/.heroku/venv/lib/python2.7/site-packages/boto/iam/connection.py", line 76, in get_response
    raise self.ResponseError(response.status, response.reason, body)
BotoServerError: BotoServerError: 505 HTTP Version Not Supported

We're using Boto 2.7.0. I though this could fix the issue when we were on 2.6.0, but it's still happening. Not sure if should we update to 2.9.7 and if it will fix this issue, so first I'd really like to understand the problem.

Thanks,

Fernando