JPanel not always painting everything

[ekted]

When I run any Java application and quickly move another window over the top of it, little horizontal and vertical slivers of white are sometimes left behind. I first noticed this when working on my own Java stuff, but it also happens when running apps directly from the Sun Java site. Is this a common problem? Is there a way to prevent it? I know under native Windows that this happens when you try to draw directly to the top-level window's client area instead of creating a child window. Is this perhaps a result of Java light-weight components doing the same thing with the underlying native windows?

Windows XP SP3, Java 1.6

Attached in an image of this happening with a Sun sample app.