We still seem to be having this problem even with the daily build from 2006-06-06. We are connecting to wildfire from the Mule 1.3-rc ESB and we're seeing random results wich is very frustrating. Please help! At least advise where we can put some sleeps (although putting sleep in a application container gives me the chills). Shoudn't this issue to be addressed in the Smack library as discussed here http://www.jivesoftware.org/community/thread.jspa?messageID=119537&#119537 and here http://www.jivesoftware.org/community/thread.jspa?threadID=19926&tstart=0 ? Could it be that this error happens because Mule builds with Smack 1.5 http://www.jivesoftware.org/community/thread.jspa?threadID=20092&tstart=0 ?

It was a timing issue. The server was sending <proceed> and then started to build the TLS setup. Clients where sometimes faster than the server and started to request TLS and the server then responded that TLS was not supported. The solution is to build the TLS setup first, then send the <proceed> and finally start the handshake.