In D&D 3.5, a character with multiple classes suffers an XP penalty if two of their classes are more than one level apart, but favored class is ignored for that purpose. (Player's Handbook, p.60).
Do prestige classes count for this purpose?
For example, a dwarf level 7 cleric takes a level in warpriest. Does he now suffer an XP penalty because his two classes, cleric and warpriest, are more than one level apart, and neither of them is his favored class? Or are prestige classes ignored for the purpose of the multiclassing XP penalty?