Displayed screen content is unstable. Some icons and lines correctly displayed may become not visible in a totally random manner. Or a whole page might appear empty/faint, while actually they have a content.
The problem appears (only?) when using “Files” at the launch bar. I guess that is the name for Nautilus file browser in Unity.
Opening folders, the contents (icons and text) might be dislayed fully on the whole screen (or not at all) in the first seconds. But anything present on display may become faint or totally invisible very soon later.
They vanish mostly when mouse is moved vertically over , while the rest of the displayed lines remain visible until mouse is moved over. Coming back to the same spot, the content might become visible again, e.g. by right click; or some action might trigger renewing the page correct display again. (e.g. click on List icon)
Windows XP has no such problems on same machine. The drivers for the old Nvidia videocard in Ubuntu might not be adequate, but I doubt it, because Linux internet browsers show all webpages as normal. Thank you for assitance.