I updated to pidgin version 2.4.2 and got problems with my jabber account. This is due to me using TSL/SSL encrypted connections. Pidgin thinks that the used certificate is not valid. One needs to manually import it to pidgin. This is described in several tutorials on the net:

Use openssl to get the certificate. You need to run

openssl s_client -connect <your_jabber_server_here>:5223

Abort openssl using Strg+C after the startup. Openssl will print the lines

-----BEGIN CERTIFICATE-----
lots of stuff...
-----END CERTIFICATE-----

You need to copy these (including the begin- and end-certificate lines) and save them to a file. Then fire up pidgin and go to the menu "Tools->Certificate". Now add the a new host and choose the saved file. After that, pidgin should be able to connect to the jabber-server with TSL/SSL again.