Damage Output Counter Wrong

[Amidamarujhqz]

I'm playing DDO in a Macbook Pro.
Since the beginning of the game I've noticed that the damage counter above my enemies never get higher.
Basically I've seen only numbers ranging from 0 to 12 when I know I'm dealing far more damage since I'm playing as a warlock on Lv 18.
Links to my pictures about the issue:
https://drive.google.com/open?id=0B8...EdkRE5TX0FkVlk
https://drive.google.com/open?id=0B8...nlFQmRhTHdNamM
Thanks in Advance
Amidamarujhqz