Ok, so I've been chasing this one for a while. I've repeatedly reset (cleared all caches, history, plug-ins, etc) Safari. I only just discovered that what ever is going on is effecting Chrome as well, but not Firefox. The easiest place that I've found to demonstrate it is by trying to go to Vimeo.com, which looks like the attached image. In Firefox it comes up properly. In Chrome it looks similar to Safari. (I only recently downloaded Chrome, and only just thought to try Vimeo there.) I've reinstalled the operating system (nominally doing a clean install). I'm kinda out of ideas short of erasing the whole drive and reinstalling onto a clean drive, and that scares the daylights out of me (not because I haven't done it before, or anything, but because it is a LOT of work to get things back up to nominal performance with all apps installed, etc., especially given that trying to do a restore from Time Machine backup could just bring the bug back...) Does anyone in this great community have any suggestions for me? Thanks!