dynamic reconfigure with libuvc_camera in jade?

edit

When I launch the dynamic reconfigure plugin and click on my Logitech C930e running as a libuvc_camera camera_node, using jade and Ubuntu 14.04, I get this error:

 Traceback (most recent call last):
  File "/opt/ros/jade/lib/python2.7/dist-packages/rqt_reconfigure/node_selector_widget.py", line 267, in _selection_changed_slot
    self._selection_selected(index_current, rosnode_name_selected)
  File "/opt/ros/jade/lib/python2.7/dist-packages/rqt_reconfigure/node_selector_widget.py", line 217, in _selection_selected
    item_widget = item_child.get_dynreconf_widget()
  File "/opt/ros/jade/lib/python2.7/dist-packages/rqt_reconfigure/treenode_qstditem.py", line 154, in get_dynreconf_widget
    self._param_name_raw)
  File "/opt/ros/jade/lib/python2.7/dist-packages/rqt_reconfigure/dynreconf_client_widget.py", line 63, in __init__
    self.reconf.config_callback = self.config_callback
  File "/opt/ros/jade/lib/python2.7/dist-packages/dynamic_reconfigure/client.py", line 271, in set_config_callback
    self._config_callback(self.config)
  File "/opt/ros/jade/lib/python2.7/dist-packages/rqt_reconfigure/dynreconf_client_widget.py", line 86, in config_callback
    widget.update_value(config[widget.param_name])
  File "/opt/ros/jade/lib/python2.7/dist-packages/rqt_reconfigure/param_editors.py", line 439, in update_value
    self._update_signal.emit(self.values.index(value))
ValueError: -313638240 is not in list

And no reconfiguration is possible.

This is with the very latest libuvc and libuvc_camera.

With dynparam I can see that scanning_mode has large random values like the -313638240 that generated the plugin errors above:

rosrun dynamic_reconfigure dynparam get /front/cam/uvc_camera 
{'white_balance_RV': 0.0,
'white_balance_BU': 0.0,
'groups': {'groups': {},
'timestamp_method': 'start',
'sharpness': 0,
'height': 360,
'tilt_absolute': 0,
'parameters': {},
'privacy': False,
'scanning_mode': -313638240,
'auto_focus': False,
'width': 640,
'type': '',
'white_balance_temperature': 2926,
'camera_info_url': '',
'auto_exposure': 0,
'vendor': '0x0',
'frame_id': 'camera',
'pan_absolute': 0,
'gain': 32623,
'backlight_compensation': 0,
'name': 'Default',
'brightness': 0,
'video_mode': 'uncompressed',
'focus_absolute': 32767,
'white_balance_BU': 0.0,
'hue': 0.0,
'saturation': 0,
'auto_exposure_priority': 0,
'serial': '',
'id': 0,
'index': 1,
'power_line_frequency': 0,
'iris_absolute': 2.9145808e-316,
'roll_absolute': 0,
'white_balance_RV': 0.0,
'state': True,
'contrast': 0,
'product': '0x0',
'exposure_absolute': 0.0333,
'parent': 0,
'frame_rate': 5.0,
'auto_white_balance': False,
'auto_hue': False,
'gamma': 1.0},
'hue': 0.0,
... and the parameters appear to repeat

Many parameters I try to change from the command line result in scanning_mode warnings:

[ WARN] /front/cam/uvc_camera /home/lwalter/catkin_ws/src/libuvc_ros/libuvc_camera/src/camera_driver.cpp:123 : Unable to set scanning_mode to 0
[ WARN] /front/cam/uvc_camera /home/lwalter/catkin_ws/src/libuvc_ros/libuvc_camera/src/camera_driver.cpp:129 : Unable to set gain to 40000

I also tried this with a Webcam Pro 9000 with the same results.