Hi GH6c5d53a52c3089,
Sorry to hear that you're experiencing some unstable tracking with your Leap Motion Controller. The entire top panel of the controller is tinted all the way through so I do not believe anything is obscuring the LED sensor.
It sounds like your controller may not be calibrated. Could you please try opening up the Leap Motion Control Panel and click on the Troubleshooting tab. On the left side, there is an option to recalibrate your controller. Once you have recalibrated successfully, please try running the visualizer again to see if the tracking improved.
You can find a youtube video with calibration instructions here: https://www.youtube.com/watch?v=s6mm4310Sp0
Jon
Leap Motion Support