Race condition when spawning turtlebot in gazebo [closed]

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I'm trying to simulate a turtlebot in Gazebo using the turtlebot_gazebo package in turtlebot_simulator v1.0.1 in ROS Fuerte. When I roslaunch turtlebot_empty_world.launch, the turtlebot spawns just fine in Gazebo.

However, if I remove the robot.launch include line from the launchfile, and then launch robot.launch after gazebo has had sufficient time to start, the turtlebot does not spawn completely. All I see are the left and right wheels in the Gazebo GUI. The rest of the robot is non-existent.

Below is the xml for turtlebot_empty_world.launch:

<launch>
  <!-- start gazebo with an empty plane -->
  <param name="/use_sim_time" value="true" />

  <node name="gazebo" pkg="gazebo" type="gazebo"
        args="-u $(find turtlebot_gazebo)/worlds/empty.world"
        respawn="false" output="screen"/>
  <node name="gazebo_gui" pkg="gazebo" type="gui" />

  <include file="$(find turtlebot_gazebo)/launch/robot.launch"/>
</launch>

Has anyone had issues spawning a turtlebot in an already existing Gazebo environment? If so, did you have to do any sort of workaround to ensure that the turtlebot spawned correctly?

Thank you for your help.