Reproduce Steps:
1. On QuickSilver06, jre1.4.2_04-b02, mozilla1.4.1(2004/02/01)
2. Start mozilla to visit a page contents java swing. For example, http://java.sun.com/docs/books/tutorial/uiswing/layout/FlowDemo.html
3. Click here to see a FlowLayout in action, in the pops up window, randomly click a button. The button became gray and after a while it bounced.
4. The delay performance also appears in following cases: select item in pull down menu; switching input method.
5. There is no other programs running when doing the testing. It is irrelevance to the machine.