FULL PRODUCT VERSION :
java version "1.7.0"
Java(TM) SE Runtime Environment (build 1.7.0-b147)
Java HotSpot(TM) 64-Bit Server VM (build 21.0-b17, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Windows 7 64bit [ version 6.1.7600 ]

A DESCRIPTION OF THE PROBLEM :
Swing is ignoring the first click after decreasing system's date and time settings.

The complete description of the situation and a workaround is this question at StackOverflow:
http://stackoverflow.com/questions/7584924/swing-ignores-first-click-after-decreasing-windows-time

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Swing application running.
Decrease system's date and time settings (e.g. change time from 15:00 to 14:00).
Notice that the first click in the Swing application does not fire any action.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Button get pressed.
ACTUAL -
Mouse click ignored.

REPRODUCIBILITY :
This bug can be reproduced always.

CUSTOMER SUBMITTED WORKAROUND :
Change value of "multiClickThreshhold" field of "AbstractButton" class to Long.MIN_VALUE (using java.lang.reflect.*).