After upgrading to 8.04, I found a strange bug: my sound worked normally from the internal speakers, but when I plugged in a set of headphones, no sound came out.
I scratched my head for a while trying to work this out till I found the workaround recommended here.
Basically all you need to do is right-click on the Volume Control applet, select Open Volume Control, then Edit -> Preferences. Check the box for “Surround,” then close the Preferences window and unmute the track marked “Surround.” That should do it.
