I installed nspluginwrapper using alien as described at MozDev.org (making sure that linux32 was already installed via Synaptic). I downloaded the Flash 9 installer and put the enclosed libflashplayer.so in /usr/lib/browser-plugins. And, again as described at MozDev.org, I ran nspluginwrapper with that file.

The Firefox about:plugins page indicated that the Flash 9 plugin was loaded. However, when I tested it on a site with Flash (in this particular case it was MPtv) the movies played fine but there was no sound. I wasn’t sure why that was because Flash 9 uses ALSA and so does Ubuntu.

I searched around on the web a bit, but didn’t find any solutions that really fit my problem (or were within my level of expertise). I decided to look in Synaptic to see if maybe I didn’t have all of the ALSA packages installed. This led me to the lib32asound2 package which is labelled as a 32bit version of the ALSA library. Once that was installed the Flash sound worked perfectly fine.

So now I’m able to properly waste time with YouTube and its many siblings.