Beginner tutorial - cannot run roscore

edit

So I'm incredibly new to ROS (and I'm no Ubuntu master, either) and I've been following the beginner tutorial to the letter. When I try to run roscore (at the appropriate point) I get this print-out:

... logging to /home/liz/.ros/log/336fd2b2-d7fe-11e1-8326-e02a82da7f54/roslaunch-ubuntu-3375.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://ubuntu:52747/
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 [3391]
ROS_MASTER_URI=http://ubuntu:11311/

setting /run_id to 336fd2b2-d7fe-11e1-8326-e02a82da7f54
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 [3404]
started core service [/rosout]

The system then hangs. Running roswtf gives this:

ERROR The following packages have rpath issues in manifest.xml:
 * beginner_tutorials: found flag "-L/opt/ros/fuerte/lib", but no matching "-Wl,-rpath,/opt/ros/fuerte/lib"
 * std_msgs: found flag "-L/opt/ros/fuerte/lib", but no matching "-Wl,-rpath,/opt/ros/fuerte/lib"
 * roscpp: found flag "-L/opt/ros/fuerte/lib", but no matching "-Wl,-rpath,/opt/ros/fuerte/lib"

I'm running Ubuntu 12.04 (Windows Installer version). I've tried fixing any network configurations (as suggested by the tutorial) and fixing manifest.xml to include the matching -Wl,-rpath,/opt/ros/fuerte/lib". I can't find anything else that fits the problem I'm having, and I'd appreciate any help!