This is from the Ghostwalk book. It seems a little weird to me, but maybe it's right. I don't know. It's been too long since I played 3.0, but I'm pretty sure at the time even the original version of the fav enemy was just a standard +1, so it kind of makes sense that the 3.0 feat that gave you more fav enemies would give you the same number.
Here's the original:
Extra Favored Enemy [General]
You select an additional favored enemy.
Prerequisites: Base attack bonus +5, favored enemy.
Benefit: You add a new favored enemy to your list of foes. Initially, you gain the standard +1 bonus on certain skill checks and on damage rolls against this new favored enemy. When you advance beyond the level at which you gained Extra Favored Enemy, this bonus increases as other favored enemy bonuses do (by +1 at 5th, 10th, 15th, and 20th ranger level). For example, suppose you select goblinoids as your first favored enemy when you are a 1st-level ranger and magical beasts as your second when you reach 5th level. Then you take Extra Favored Enemy as your feat at 6th level and select aberrations. At this point, you have a +2 bonus against goblinoids and a +1 bonus against both magical beasts and aberrations. When you reach 10th level, your bonuses rise to +3 against goblinoids and +2 against magical beasts and aberrations.
Here's the one I updated:
Extra Favored Enemy [General]
You select an additional favored enemy.
Prerequisites: Base attack bonus +5, favored enemy.
Benefit: You add a new favored enemy to your list of foes. Initially, you gain the standard +2 bonus on certain skill checks and damage rolls against this new favored enemy. When you advance beyond the level at which you gained Extra Favored Enemy, this bonus increases as other favored enemy bonuses do (by +2 at 5th, 10th, 15th, and 20th ranger level). For example, suppose you select goblinoids as your first favored enemy when you are a 1st-level ranger and magical beasts as your second when you reach 5th level. Then you take Extra Favored Enemy as your feat at 6th level and select aberrations. At this point, you have a +4 bonus against goblinoids and a +2 bonus against both magical beasts and aberrations. When you reach 10th level, your bonuses rise to +4 against goblinoids and +4 against magical beasts and aberrations.