Hey guys: I've gone through two 13" mbas (1.86/4gb, ultimate) and both have had inversion or pixel walk screen issues. Any time i scroll through webpages pixels will shift very subtely - for instance in macrumors archive those fine lines that box in posts will blur when actively scrolling up/down. I can't find any definitive posts on what causes this aside from voltage issues w/lcd. The folks at genius bar were not helpful. This site: http://www.lagom.nl/lcd-test/inversion.php has some examples. Another thread on the issue https://discussions.apple.com/thread/2675037?threadID=2675037&tstart=43 Does anyone know if this is an issue with all the 13'' mbas? It's a small issue but really bothers me, especially since I scroll and read through tons of text and the flickering becomes pretty apparent. Any advice on solutions or general thoughts on what the issue is exactly would be appreciated. At this point I'm going to try a third 13'' ultimate and see if I get the same problem.