java version "1.4.1"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.1-b21)
Java HotSpot(TM) Client VM (build 1.4.1-b21, mixed mode)

For a multi-monitor environment like Linux, if the monitor setup is like this:

    -------------
    |     |     |
    |  0  |  1  |
    |     |     |
    -------------

If the browser window on screen 1, any tooltips in that applet will appear on screen 0.

To reproduce: 

Load the SwingSet2 applet into the browser (Mozilla 1.2.1). 

http://java.sun.com/products/plugin/1.4.1/demos/jfc/SwingSet2/SwingSet2.html

Look at the tooltip demo or observe the tooltips from the toolbar.

The tooltips are in the correct place when the browser is in screen 0. If the browser is on screen 1 then the RIGHT edge of the tooltips will be against the RIGHT edge of screen 0. 

This problem doesn't occur when the application is run standalone.

Environment: Red Hat Linux 8.0, J2SE 1.4.1 (including plugin), Mozilla 1.2.1.