Hi all, I'm a newbie on Ubuntu but have almost completely made the switch, having not used Windows once in the past 3 weeks. I'm really enjoying Ubuntu and OpenOffice etc. etc. I'm still having some trouble with Ubuntu configuration though, and it's driving me nuts.  Some of the help and forums I find online are useful, but I can't get to the bottom of these three things and wondered if there is anyone who can help me on my machine for an hour or so here in Rondebosch: 1.  Screen refresh rate; the flicker is too much for me and I'm getting headaches.  I've followed instructions I found online, including overclocking the monitor, but still can't iron it out.  Under identical settings on Windows XP Pro I have no problems. 2.  Sound: there is none.  I'm particularly clueless when it comes to hardware and drivers and would really like to get some sound coming out of the speakers. 3.  Medibuntu - I get the white screen of death whenever I run GoogleEarth, and the online forums haven't helped. Other problems I've encountered are with the Java Runtime Environment installation and installing Freemind (mind-mapping software). I'd be most grateful to anyone with expertise who can help sort out these problems! Freedom, Dave