H1. sudo apt-get install flashplugin-nonfree-extrasound

2. change location of firefox cache (e.g., to tmpfs):

1. assmume /tmp/foo/firefox.cache exists and /tmp is mounted as tmpfs
2. open firefox
3. enter uri of about:config
4. add or modify entry 'browser.cache.disk.parent_directory' to point to '/tmp/foo/firefox.cache'