Description of problem: xulrunner is being rev'd for 5.3, therefore need to make sure the corresponding firefox gets into the trees. Presently 3.0-2.el5 is being pulled into the nightly trees, but that's incompatible with xulrunner-1.9.0.2-3.el5. Please ensure firefox-3.0.2-2.el5 (or later) gets tagged appropriately.
Confirmed in the 20080922.{0,4} trees.