Ex-"class" and multiclassing XP penalty

[Yogibear41]

I know alot of people simply ignore the multiclassing XP penalty, but if that particular rule was in place, would a character who was an X-Class still en-cure a multi-classing penalty? For example say a character with Fighter as his favored class begins his career as a chaotic barbarian, but then by time he reaches level 2 he becomes civilized if you will becoming lawful and begins taking levels in something else. If he becomes an X-Barbarian1/Other Class 3 does he begin taking an xp penalty?

I think the answer is yes, but if I am missing something that would be great.

[bekeleven]

Yes, unless the other thing is fighter. He'd have a minus because his classes are not within one level of each other.

Favored class: Fighter means you can ignore all fighter levels when calculating the penalty.

Note also that prestige (and paragon) classes are not counted either.

[Thurbane]

There are also some feats that let certain classes not count against your multiclassing XP penalty.

And Dragonborn adds Fighter to any existing favored class(es).

[The Grue]

Yes, unless the other thing is fighter. He'd have a minus because his classes are not within one level of each other.

Favored class: Fighter means you can ignore all fighter levels when calculating the penalty.

Note also that prestige (and paragon) classes are not counted either.

What's that idiom about, the more exceptions there are to a rule the worse that rule is?