After upgrading my Macbook Pro from 10.7.2 to 10.7.3 one of my vertically rotated external displays which uses Plugable UGA-2K-A USB 2.0 failed to come back. It kept displaying a black screen, would periodically go into sleep mode and come back, and was not recognized as one of the displays in system settings.
After restarting machine several times and unplugging and testing the display adapters, I realized the problem might be with the drivers after the update. Sure enough after visting http://www.displaylink.com/support/ma… there is a note that “There is a known issue with OSX 10.7.3 and using rotated displays. DisplayLink are investigating this issue, but until there is a solution, please do not use rotation with the 10.7.3 update”. Unfortunately once the display was already set up in rotated mode, I didn’t know how to get it out of it. If you can suggest a way, that would be great.
I ended up installing the 1.8alpha drivers from http://displaylink.org/forum/showthre… and this fixed my issues. I’m able to use the rotated monitor again.