Purple panel in display

If one panel on the screen is always completely purple

This is due to a conflict between your computer and the system used to play the video clips (QuickTime 3). The makers of QuickTime 3 (Apple) realise that this is an issue for some users and are working towards overcoming it. Keep an eye open on their website for updated versions of QuickTime 3 which will eventually fix this problem. Meanwhile, you can still play the videos by opening them in the other panels on the screen (but remember to press the pause button under the purple panel, otherwise there will be two videos playing at the same time and this will impair performance).