I am not sure if this is a hardware problem or Firefox problem but I only seem to see the behavior in Firefox. The browser screen will suddenly white out most of the text on screen and compress or distort the open tab labels. The screen captures below illustrate the problem better than I can explain it. I have updated, refreshed, uninstalled/reinstalled to no avail. Problem appeared suddenly and now happens consistently. It happened while typing this message. Top screen cap is normal browser window, middle is same page after error, bottom capture is the page I was writing this post on after another occurrence of the error.