Four regression tests are always failing on windows

This four combobox tests are failing on any windows system, 32 and 64 bit.

closed/javax/swing/JComboBox/4765319/bug4765319.java
closed/javax/swing/JComboBox/4890345/bug4890345.java
closed/javax/swing/JComboBox/4919991/bug4919991.java
closed/javax/swing/JComboBox/6559152/bug6559152.java

Fail was detected by aurora (http://aurora.ru.oracle.com/functional/faces/RunDetails.xhtml?names=494871.ute.st2-2).
Tests fail always both in aurora and manual runs.

Tested on friedrich-engels (windows 8, x86_64) and fx-sqe17 (windows 7, 32 bit)