Flash leaves ghost image in browsers, evince, possibly others

[MR ZenWiz]

On my workstation (Dell T5500) I usually run Chrome for my ongoing
usual browser, with occasional forays into Firefox and others.

A few days ago, I went to a web site (can't remember which one, darn
it) and there was a flash video up on that site.  After I left that
web page, the image of the flash video remained on the screen in the
browser's background image.  If I moved the browser window, the
artifact stays in place and will disappear if I move the browser off
it altogether, until I bring the browser back over the space on the
screen where the artifact was, and it's back.

This happens both in Chrome and Firefox (3.6 or 4.0), and today I
noticed that it also bleeds through in evince.  It does not show if I
put a terminal window over the spot, but QT also does the same thing.

It's as if there's an image in the video buffer that isn't getting
cleared out, but it only shows up in certain GUI apps.

So far, the only "cure" I've found for this is a reboot.  Exiting X or
just logging out and in does not make this go away, and I haven't
found any window type that will sweep over that area and clear it.

Any ideas?

I'm running U10.10 with one nvidia card (two screens - happens on
both), and the latest nvidia proprietary driver.

The most recent web page to do this to me was an HP web page with an
embedded video about one of their award-winning products.  I lost the
page and couldn't find it again, even with the same Google search that
brought it to me in the first place.

This usually does NOT happen with Youtube videos or other ordinary
flash presentations.