BufferedImage não cria graphics

java.awt.image.BufferedImage buffer = new java.awt.image.BufferedImage( 100, 100, BufferedImage.TYPE_INT_RGB );
java.awt.Graphics g = buffer.createGraphics();

java.lang.NullPointerException

at java.awt.image.BufferedImage.createGraphics(Unknown Source)

at app.XletApp.startXlet(Unknown Source)

at com.sun.xlet.Loader.carrega(Unknown Source)

at com.sun.xlet.XletRunner.main(Unknown Source)

at java.lang.reflect.Method.invoke(Unknown Source)

at sun.misc.CVM.runMain(Unknown Source)