Oracle released patch 6318531 on September, 7, 2007 which addresses bugs introduced after application of ATG_PF.H RUP5. Here's an excerpt from the patch readme:
This ARU delivers multiple code enhancements for the AdminAppServer.class. SomeMetalink Note 459072.1 has more details about the first bug 6351958.
of these enhancements were brought about by issues reported after the
application of 5473858 (11i.ATG_PF.H.RUP5) and is a prerequisite for this ARU.
The following issues are addressed in this ARU:
6351958: 11IRUP5:FND_JDBC SETTINGS IN DBC FILE CHANGED TO LOWERCASE
6318531: ORA-01403 FND_APP_SERVER_PKG IF USERENV('LANG') NOT AN INSTALLED LANG
5050617: ADMINAPPSERVER SHOULD RAISE ERROR IF THE GUEST_USER_PWD DOES NOT POINT
4051516: CANNOT FIX CORRUPTED GUEST USER USING FNDCPASS OR ADMINAPPSERVER
Patch 6168660 (XML PUBLISHER DOES NOT START AS POST REQUEST SERVICE PROCESS ) is another post ATG_PF.H RUP5 patch. This patch modifies the way XML publisher is called making it possible for spawned programs, including FSG, to use the facility.