Embedded Flash videos
I encountered a virus/worm on my Windows machine which I didn't feel like dealing with right away so I decided to use my Knoppix live CD for a bit. That "bit" has now turned into about two months (I procrastinate) and the entire time, embedded Flash videos (youtube, etc.) always worked fine after installing the Flash plugin. All of a sudden, today, they all look like they're refreshing really poorly. Think of what a CRT monitor looks like when you film it with a video camera... that's what the flash videos look like. If I download a regular video (mpg) it will play fine with Kaffeine, and I see no other problems with my display. What I find strange is that the change was out of nowhere. Rebooting doesn't help.