Desktop refreshing icons every 15 seconds or so

I've been on Mavericks since it was open to the general public. But yesterday it started frequently refreshing he desktop icons, over and over again, possibly every 10-15 seconds. It's very strange. I'm not moving any windows or moving the mouse around. Often I'm just reading a web page or some email and I'll notice the desktop repaint all the icons, then read a bit more, then notice it doing it again. Macbook Pro retina, Mavericks. Have noticed on 2 extern displays (Apple Thunderbolt display at work and on 1080p TV/monitor at home). Laptop itself is typically closed. I've posted other questions about desktop icon placement, not sure if any of that is related, just full disclosure.