Hypersmurf
Moderatarrrrh...
At the same bonus as the attack that dropped the previous creature.
Let's find a random quote from the SRD.
Two Weapon Fighting
If a combatant wields a second weapon in the off hand, that combatant can get one extra attack per round with that weapon. Fighting in this way is very hard, however, and a combatant suffers a -6 penalty for regular attacks with a combatant's primary hand and a -10 penalty to the attack with a combatant's off hand.
A -10 penalty to the attack. I trust you don't subtract that penalty from the damage roll as well?
"Same bonus as the attack" is "same attack bonus". The two terms are equivalent.
-Hyp.