I find that occasionally I have issues whereby my flash videos on sites like youtube, don't work properly and only a reboot fixes it.
Problems like Black screen when expanding a video to full screen, or micro pauses every few seconds. Seems to only happen after a while, but once it happens it won't go away.
Chrome updates it's own Flash Player so it won't let you update it, and I am not sure how to kill the flash process or troubleshoot why it's happening.
I run W7, x64, 18GB Memory, 2GB Video Card, SSD HDD's in Raid 0.