Someone reported this behavior in the past day or two but couldn't reproduce it. I can't find that thread anymore anyway. I have a reproducible case. Whenever I open Logos with this particular layout with my particular screen settings, it happens.
Here's a video showing the behavior: http://www.screencast.com/t/Uperpph9LWr
Here's a log file from that recorded session: 4212.TabFlickering.zip
Here's a log file from a simpler session immediately after that one, where I just opened Logos back up to the previous state it was in and observed the flickering and then closed it: 5808.Logos.log