...
((JDialog) (fw.getTopLevelAncestor())).toFront();
...
((JDialog) (fwStartedDrag.getTopLevelAncestor())).toFront();
The above fails if we use FloatingWindowProperties().setUseFrame(true). The fix is to cast to Window instead of JDialog.
FYI, Complete statck trace :
java.lang.ClassCastException: javax.swing.JFrame cannot be cast to javax.swing.JDialog
at...
2009-04-28 12:27:19 UTC in InfoNode Docking Windows