I'm using IntelliJ IDEA official connector to JIRA.
Trying to receive the list of tasks from JIRA and failed, but test connection is successful.
Java version=1.6.0_43, Java vendor=Apple Inc., OS name=Mac OS X, OS architecture=x86_64, IDEA build number=WS-127.122, Plugin version=3.0.10, SVN:1304051101
damn, this looks absolutely kosher, which means that most likely there must be some problem passing authentication credentials to your JIRA using basic authentication. I am afraid we will not get far without JIRA logs
could be a session-related issue (which I just fixed).