dear list,
after re-installing Fedora-16 XFCE, and research, it appeared that, as far as the plugin-problems of Firefox were concerned, the problem was caused by the root-rights for Firefox and .mozilla.
After changing the rights to user, my test-problem (hearing piano-player Uwe Kliemt on You Tube) was resolved.
Thanks for your attention,
With kind regards
Dick Kampman dkampman@xs4all.nl