This is a bug fix release and is source and binary compatible with 2.4.0. The main reason for this quick followup release is a problem with the button size allocation logic in 2.4.2, which showed up in the Gimp. A number of other bugfixes have been included as well.

gtk+-2.4.3.tar.bz2 md5sum: debfd0fcef08683c0761f13e1ba2dced
gtk+-2.4.3.tar.gz md5sum: bb044ceddcdb606f0591c00cafdf7894