"Exception AttributeError" on roscore launch

edit

I am receiving an error messages when I run roscore from the command line on Ubuntu 12.04. Whatever the cause, I was still able to functionally complete the beginner's section of the tutorial page.

I installed ROS (as per the installation instructions), and I set the environment variables for a single-machine network setup.

The following is the output after executing roscore from the command line:

 developer@developer-VirtualBox:~/fuerte_workspace$ roscore
 ... logging to /home/developer/.ros/log/2de0d828-ee47-11e1-a20c-080027500e36/roslaunch-developer-VirtualBox-27454.log
 Checking log directory for disk usage. This may take awhile.
 Press Ctrl-C to interrupt
 Done checking log file disk usage. Usage is <1GB.

 started roslaunch server http://developer-VirtualBox:55585/
 ros_comm version 1.8.10

 SUMMARY
 ========

 PARAMETERS
  * /rosdistro
  * /rosversion

 NODES

 auto-starting new master
 Exception AttributeError: AttributeError("'_DummyThread' object has no attribute '_Thread__block'",) in      <module 'threading' from '/usr/lib/python2.7/threading.pyc'> ignored
 process[master]: started with pid [27470]
 ROS_MASTER_URI=http://developer-VirtualBox:11311/

 setting /run_id to 2de0d828-ee47-11e1-a20c-080027500e36
 Exception AttributeError: AttributeError("'_DummyThread' object has no attribute '_Thread__block'",) in      <module 'threading' from '/usr/lib/python2.7/threading.pyc'> ignored
 process[rosout-1]: started with pid [27483]
 started core service [/rosout]

Does anyone know how to resolve this exception?

Thank you.