There is apparently a bug introduced in the latest Java update for Mac OS X, which causes deletes in JFormattedTextFields to be performed twice. See http://lists.apple.com/archives/java-dev/2010/May/msg00092.html
The DefaultEditorKit.deletePrevCharAction is invoked twice when the delete key is pressed.
Are there any suggestions for a workaround?
I'm thinking of replacing the delete action for my text fields with a patched version that somehow filters out these duplicate invocations.