Launch the regression test test/java/awt/dnd/DnDAcceptanceTest.html twice from
separate shells. As the very first DnD transfer, drag a Button from one process
to the other. The following exception is thrown:

Exception "java.lang.ClassNotFoundException: DnDSource"while constructing
DataFlavor for: application/x-java-serialized-object; class=DnDSource

The transfer occurs normally on subsequent inter-JVM transfers, or if an in-
process transfer is performed as the first transfer.

Regression from kestrel on both Windows and Solaris.