I've just upgraded from version 0.9.6.1 to the newest 1.1.1 and I noticed that when I try to open a JDateChooser (from the JCalendar 1.4 library) the calendar doesn't open correctly and it throws this ...

In this article, an excerpt from The Definitive Guide to Java Swing (Apress, June 2005; ISBN: 1590594479), John Zukowski explains how to work with the JSpinnercomponent.