I have a Ranger/Druid (3/1) with Favored Enemy: Undead.

When at wilderness areas he gains attack bonus +2 to all attacks except vs. Favored Enemy, which actually becomes a penalty.

I assume it's because bonus for Nature Sense is missed from calculation of AB vs. Favored Enemy.

The favored enemy bonus also doesn't go up when you have magic weapon/greater magic weapon/bard song up. Occasionally those can make the favored enemy become a penalty too.

I too have noticed this with my new character. I'd have +7/+8 vs. undead, then I'd cast magic weapon and have +8/+8 vs. undead - If I'm not mistaken, it should be +8/+9 vs. undead.

Aye, that is so with all Favored enemy. Did not think it's a bug though.

Any news about it?

I'm locking this thread, because there's another thread about the same bug.