The IRC Bot should have a checkbox that allows Jenkins to connect to servers using self-signed SSL certs. This is the error I'm seeing in the logs:

INFO: Jenkins is fully up and running
hudson.plugins.rake.Rvm@809791
Mar 7, 2012 8:33:30 PM hudson.plugins.im.IMConnectionProvider$ConnectorRunnable run
INFO: Trying to reconnect
Mar 7, 2012 8:33:30 PM hudson.plugins.ircbot.v2.IRCConnection connect
INFO: Connecting to irc.geoloqi.com:1337 as jenkins-bot using charset UTF-8
Mar 7, 2012 8:33:31 PM hudson.plugins.ircbot.v2.IRCConnection connect
WARNING: Error connecting to irc: javax.net.ssl.SSLException: Connection has been shutdown: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
Mar 7, 2012 8:33:31 PM hudson.plugins.im.IMConnectionProvider$ConnectorRunnable run
INFO: Reconnect failed. Next connection attempt in 1 minutes

This would avoid having to do a hacky workaround like this:

http://www.erikzaadi.com/2011/09/09/connecting-jenkins-to-self-signed-certificated-servers/