Thanks for the reply
Somehow my form (derived from JFrame) does not contain a method called 'setDoublebuffered', I don't really know why - it does contain a 'isDoublebuffered'-method, but I see no way to change it
I'm using NetBeans, not Eclipse, and it seems I'm using Java version 1.6.0_16
Edit:
What is 'rootPane'? I randomly noticed that a 'this.rootPane.setDoublebuffered'-method does exist. It doesn't solve the problem though