Normally I work on a MacBook Pro with an external monitor attached. The laptop is closed, so the external monitor is the only screen in use. In this configuration, web start applications and applets and other standalone code works fine.
However, when I disconnect the external monitor and switch to the laptop display the same applications often stop drawing text. In the attached case, the button label and text area content draws correctly, but if you resize the window small enough so the scroll area shows scrollbars the text stops drawing. I am not sure if the scroll pane is important or not, but it readily reproduces the problem.
Test case attached. 'before.png' shows the state before the problem occurs, 'after.png' shows the state afterwards.