For the last couple of months, I can be browsing the YouTube web site, not watching a video, and all of a sudden, audio from a advertisement will start playing. Sometimes, this audio will start playing along with a video I'm watching. If I close out that tab in Firefox, it stops. I've had this happen even while I'm doing something completely different on the machine and YouTube has been setting idle for long periods of time.
I have all the pop-ups blocked, etc.
Anybody else experiencing this? Any suggestions?