Bukkit

What steps will reproduce the problem?
1. Wear Armor
2. Get hit by something what does over 20 damage; but you would survive cause of the armor
3. You regenerate

What is the expected output? What do you see instead?
It is expected that the armor will block most of the damage and you loose like 3 hearts.
You regenerate instead

What version of the product are you using?
0.3

Do you have an error log of what happened?
Nope

Please provide any additional information below.
I think you are using a formula like current health - damageAmout its working perfectly if you recieve less damage then health left; or when you aren't wearing any armor so I think the plugin isn't calculating the armor protection.

Hmm... I thought the event I was using took the armor protection into account already. I'll look into it.