Sometimes flash just doesn't produce sound, or you can find flash will "give up" playing sound after a given period. Use this fix to stop that.
Easy as pie.
Open terminal, and enter:
Wait for the install to complete, before typing:Code:sudo aptitude install alsa-oss
A file will open, and in the file you will see:Code:gksudo gedit /etc/firefox/firefoxrc
Change this to:FIREFOX_DSP=”none”
Hope this helps you all.FIREFOX_DSP=”aoss”
Update: I have been notified that this also works on Firefox clones/forks such as "Flock"