Bring up notepad, open readme.txt in java2d demo directory. Make window slightly wider so that horizontal scrollbar disappears, and slightly shorter. Continually scroll up and down with the mouse fast. At some point the text starts smearing and becomes unreadable. Cursoring over the text does not immediately fix it either.
This is with build 89, and happens on both 98 and NT, I couldn't get it to happen on Solaris.