I'm not sure if the bug is actually in Trafficlight, Chrome browser or Linux but here's the gist.
I use the built-in Ctl+P (pint) function on Google Chrome browser (on Ubuntu) to create PDFs of webpages for later reading.
When creating the PDF of a page the Trafficlight drop-down menu is being captured and inserted into one of the created PDF pages.
As an example, if I create a PDF of the Microsoft keyboard-shortcut list website:
http://support.microsoft.com/?kbid=301583
If the page is scrolled all the way to the top then it doesn't happen but if the page is scrolled down even a few lines then the Trafficlight drop-down menu displays within the captured pages upon completion of the PDF Printing (after the PDF is created).
I have a feeling that it is more likely that this minor bug has to do with Chrome than with Trafficlight but I thought that it was still worth mentioning.