Following on from my earlier musings of the subject, I finally have got the BBC’s iPlayer going on my Ubuntu set up. To do this, I needed to get my hands on the plug-in files nphelix.so and nphelix.xpt. Once that was done (more on how I did that later), I popped the former into /usr/lib/firefox/plugins, the latter into /usr/lib/firefox/components and restarted Firefox. I think that a system restart might have helped me too, even if it was done another reason. The files themselves were culled from the RealPlayer folder populated by the installer (realplay-10.0.9.809-linux-2.2-libc6-gcc32-i586.bin was what I used) that I had downloaded from the Helix Community website; the plugin files were found in the mozilla subfolder under RealPlayer.
Another thing that I did was to fire Alacarte, Gnome’s menu editor and add Configuration Editor (also known as GConf, I believe) to the System tools submenu on the Applications menu. Once added to the menu, I fired up the said application. Navigating to desktop>gnome>url-handlers>rtsp, I changed the command to realplay "%s". I don’t know if this helps but it certainly was no hindrance and I got the result that I wanted and in high quality audio too.