The problem only happened on Win98. It does not happen on WinNT or Win2000.
The problem freeze the whole screen. I have to hard reboot the system.
When I ran the Drag and Drop test suite, before the test cases start
running the screen and keyboard all freezed. The test suite is
located at /net/sqesvr/export/disk1/dnd_ws/DnDQLMerlin.

I use -verbose to print out the classes as follow:

[Loaded dndTester$2]
[Loaded javax.swing.MenuElement from Z:\JDK1.4\WIN32\JRE\lib\rt.jar]
[Loaded javax.swing.JMenuItem from Z:\JDK1.4\WIN32\JRE\lib\rt.jar]
[Loaded javax.swing.JMenu from Z:\JDK1.4\WIN32\JRE\lib\rt.jar]
[Loaded javax.swing.JToolBar from Z:\JDK1.4\WIN32\JRE\lib\rt.jar]
[Loaded javax.swing.tree.VaribleHeightLayoutCache$VisibleTreeStateNodeEnumeration
 from Z:\JDK1.4\WIN32\JRE\lib\rt.jar]
[Loaded sun.awt.image.BufImgSurfaceData$Argb from Z:\JDK1.4\WIN32\JRE\lib\rt.jar]
[Loaded sun.java2d.loops.drawStringARGB from Z:\JDK1.4\WIN32\JRE\lib\rt.jar]
[Loaded sun.java2d.loops.drawCharsARGB from Z:\JDK1.4\WIN32\JRE\lib\rt.jar]
[Loaded sun.java2d.loops.drawBytesARGB from Z:\JDK1.4\WIN32\JRE\lib\rt.jar]
[Loaded sun.java2d.loops.drawGlyphVectorARGB from Z:\JDK1.4\WIN32\JRE\lib\rt.jar]
[Loaded sun.java2d.loops.paintArgbOntoS565 from Z:\JDK1.4\WIN32\JRE\lib\rt.jar]