A. approached me that on her computer after the upgrade to Kubuntu Lucid Lynx there was no sound in the Firefox flash plugin, system sound and CD worked fine though. No, PulseAudio is not installed.. I remembered that I had to change something already for Karmic and luckily documented the change, but actually didn't publish, shame on me ;-) Apparently that change got overwritten by the upgrade. So here is what may help if you got no sound in flash and the command lspci | grep -i audio
displays something like 00:1b.0 Audio device: Intel Corporation N10/ICH 7 Family High Definition Audio Controller (rev 01)
and cat /proc/asound/cards
gives something like 0 [Intel ]: HDA-Intel - HDA Intel HDA Intel at 0xf9ffc000 irq 16
and head -n 1 /proc/asound/card0/codec*
for example gives Codec: VIA VT1708S

As root or sudo'ed edit /etc/modprobe.d/alsa-base.conf and append the line options snd-hda-intel model=auto
Save and quit editor ;-)
You could then either stop all programs that might use sound and alsa-utils stop and try rmmod snd_hda_intel and hope nothing uses it anymore, which can be checked by lsmod | grep snd_hda_intel where the second number should be 0, and then modprobe -v snd_hda_intel and alsa-utils start, or simply reboot instead.. yeah, that's lame and reboot is ugly, but hey I'm lazy ;-)
There's a page in the Ubuntu wiki, HdaIntelSoundHowto tells how to lookup information in /usr/share/doc/alsa-base/driver/ALSA-Configuration.txt.gz and /usr/share/doc/alsa-base/driver/HD-Audio-Models.txt.gz, alas the VT1708S is not mentioned in those. However, the ALSA project claims to support it since at least v1.0.18, just that there don't seem to be specific model options available. A similar page in the German ubuntuusers.de wiki is Soundkarten installieren/HDA.
Btw, this was with an ASUS P5KPL-AM EPU board specified to have a VT1708 High Definition Audio 6-Channel Codec, for the search engines..

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