I'm pretty much having the same issue, downloaded today from http://sourceforge.net/projects/jbpm/files/latest/download?source=files
Ran the demo setup and script referenced on http://docs.jboss.org/jbpm/v5.1/userguide/ch03.html
Tried to run the example in section 3.4 of the user guid and nothing shows up under the Process Instances, Process Instance, or Human Task View in eclipse, though they are listed in the console discussed in section 3.5.