See this: [http://kb.mozillazine.org/Popups_not_blocked]

2 times i have sent a message with the same problem. got 2 different answers and neither has worked. pop-ups come up and the sound starts. exit out and the sound is still heard with no way to stop it unless i close out firefox. this is ridiculous, i don't have this problem with windows explorer.

I have the same problem with Firefox 3.6.6 except that the sound does turn off. I have blocked each site and a new one appears each time I start Firefox.

See [[Pop-up blocker]] for troubleshooting information on why pop-ups are not being blocked. A pop-up from Firefox will have the Firefox logo and it will say Mozilla Firefox on top (See [https://support.mozilla.com/en-US/kb/Pop-up+blocker?bl=n&s=pop%2520up%2520blocker#Is_the_pop_up_coming_from_Firefox_ Is the pop-up coming from Firefox?] for more information.) Attached is an example. If you determine the pop-ups are not coming from Firefox: Your issue may be caused by Malware. You can run and update the following '''free''' antivirus software: 1. Malwarebytes (Free version) - http://www.malwarebytes.org 2. Spybot Search & Destroy - http://www.safer-networking.org 3.Spyware Terminator - http://www.spywareterminator.com In addition, there are a number of forums you can use to help get rid of your infection. These include: *[http://www.bleepingcomputer.com/forums/ Bleeping Computer] *[http://forums.spybot.info/ Safer-Networking Forums] *[http://www.spywarewarrior.com/index.php Spyware Warrior Forums] *[http://www.spywarewarrior.com/index.php SpywareInfo Forums]