Loading Ultimate Combat causes spurious Perception subskill to appear

The Perception sub-skill "Perception (Notice unusual stonework/Underground) from Ultimate Combat is coded in a way that causes it to appear under certain circumstances when not appropriate. This happens with any character that has at least one rank in Perception and for whom Perception is a class skill.

The problem here seems to be that this is actually 1) a skill usable untrained, and 2) a sub-sub-skill that inherits from "Perception (Notice unusual stonework)", but for the double inheritance the display check seems to disregard the +3 class skill bonus.

Reproduce: Create new character, for example, human bard level 1. Add one rank in Perception. Check skill list on character sheet.