for completeness: the openssl output from the machine, where python 2.7 is working:

fertig@hornisse:/home/fertig > openssl s_client -connect 172.23.6.222:443
CONNECTED(00000003)
depth=1 C = DE, L = Munich, O = Siemens AG, OU = Com Enterprise Systems, CN = Siemens Com ESY HD Security Office, emailAddress = hipath_security_office@siemens.com
verify error:num=19:self signed certificate in certificate chain
verify return:0
---
Certificate chain
 0 s:/C=DE/L=Munich/O=Siemens Enterprise Communications/OU=Enterprise Systems/CN=optiPoint - WBM
   i:/C=DE/L=Munich/O=Siemens AG/OU=Com Enterprise Systems/CN=Siemens Com ESY HD Security Office/emailAddress=hipath_security_office@siemens.com
 1 s:/C=DE/L=Munich/O=Siemens AG/OU=Com Enterprise Systems/CN=Siemens Com ESY HD Security Office/emailAddress=hipath_security_office@siemens.com
   i:/C=DE/L=Munich/O=Siemens AG/OU=Com Enterprise Systems/CN=Siemens Com ESY HD Security Office/emailAddress=hipath_security_office@siemens.com
---
Server certificate
-----BEGIN CERTIFICATE-----
MIIEwDCCA6igAwIBAgIBFjANBgkqhkiG9w0BAQUFADCBtDELMAkGA1UEBhMCREUx
[..]
dEYuDjj21U+xronZ0FYVieIP1jk=
-----END CERTIFICATE-----
subject=/C=DE/L=Munich/O=Siemens Enterprise Communications/OU=Enterprise Systems/CN=optiPoint - WBM
issuer=/C=DE/L=Munich/O=Siemens AG/OU=Com Enterprise Systems/CN=Siemens Com ESY HD Security Office/emailAddress=hipath_security_office@siemens.com
---
No client certificate CA names sent
---
SSL handshake has read 2748 bytes and written 407 bytes
---
New, TLSv1/SSLv3, Cipher is AES256-SHA
Server public key is 1024 bit
Secure Renegotiation IS NOT supported
Compression: NONE
Expansion: NONE
SSL-Session:
    Protocol  : TLSv1
    Cipher    : AES256-SHA
    Session-ID: 506EDFB9B197A00F67A43F34B3313B660DBC64FF7353112836F813723B30071C
    Session-ID-ctx:
    Master-Key: 6928F9EF19DB7DBEEEA6D09392EF2F848613E40C1B6CE6226C342AB3D211AA1A8E04EF27BDEE4CD03AB4F6AD7317EBB3
    Key-Arg   : None
    PSK identity: None
    PSK identity hint: None
    Start Time: 1349443513
    Timeout   : 300 (sec)
    Verify return code: 19 (self signed certificate in certificate chain)
---
GET / HTTP/1.1

HTTP/1.1 400 Bad Request
Date: Fri, 05 Oct 2012 15:25:21 GMT
Server: Virata-EmWeb/R6_2_0
Connection: close

400 Bad Request