Web Client for Chrome in a playlist with "random" enabled plays two songs at once

[lgamal]

Title says most of it ... navigating to play.spotify.com/?http=1 then selecting a playlist ... if I enable random song selection, occasionally (once every 2 hours or so of listening) two songs will begin playing at once when the previous song ends. After about 5 seconds it seems to catch itself and kill one of the songs. Another symptom is that an advertisement and a song will begin playing at once, but neither will end early. That is, the phenomenon of both playing at once remains until the first of the two ends (most likely the advertisement). 

How do I file a support ticket for this item? It seems nonproductive to pose this question toward the community, unless there are settings available which can prevent this from occuring. But in that case, why is the feature available to have an advertisement and a song playing at once? Thanks.