Ok, this seems to solve the problem in it finding the properties file and starting up. Is the following what you expected?:
C:\jbpm>ant start.human.task
Buildfile: C:\jbpm\build.xml
start.human.task:
[javac] C:\jbpm\build.xml:864: warning: 'includeantruntime' was not set, defaulting to build.sysclasspath=last; set to false for repeatable builds
[echo] before classname
[java] Task service registered usergroup callback ...
[java] Task service started correctly!
[java] Task service running ...
Also, the process still runs in the foreground. When I install the demo application, and use "ant start.demo", all processes run in the background, including the human task service. Is there a way to get the task service to run in the background when it's started by itself (which install.html says you can do).