button changes it's size on mouse hover.
see screenshots attached.
to reproduce the bug, use test suite from http://shaman.russia.sun.com/hg/index.cgi/java-client/
(see Scenegraph, Layout2app )
run Layout2app, press VBox button: several vboxes appear. move mouse over the button in upper-left vbox - thr button changes it's size
without any visible reason.
same bug with hardware and software rendering.
same bug is reproducible with button inside of VBox, HBox, FlowPane, TilePane.
The test application it quite large for this case, but the bug is not reproducible in simple cases.