(I\'ve asked the same question of the jmeter-user mailing list, but I wanted to try here as well - so at the least I can update this with the answer once I find it).
Try searching your classpath (in Eclipse, I do ctrl-shift-t to do this) for SSLSocketFactory*. If you find one, set it as a property on the Security class:
In my environment, I've found the following two:
Security.setProperty("ssl.SocketFactory.provider", "com.ibm.jsse2.SSLSocketFactoryImpl");
or
Security.setProperty("ssl.SocketFactory.provider", "com.ibm.websphere.ssl.protocol.SSLSocketFactory");
(or for whatever other class you find)
Similarly for ServerSocketFactory
, if you need server sockets.