1. Deleted all msn/live/hotmail certificates in the folder
2. went to https://omega.contacts.msn.com using fire fox (https not http)
3. right click > view page INFO > Security Tab > View Certificate Button > Details Tab > Export Button
4. Saved the file to ~.purple/certificates/x509/tls_peers/omega.contacts.msn.com
Like many people, I started getting certificate errors when connecting to my MSN account using Pidgin. The straightforward fix described (delete certificate, reconnect to fetch the new one) didn’t work for me with Pidgin 2.7.5 under Windows 7, but this slightly-more-convoluted technique worked fine.