Disruption Shield collapse does extra damage.

[sugaraddict]

Playing an aether/arcane archmage and my disruption shield collapses increasing the damage received from 50 damage to 317 damage if I'm reading it correctly.
Picture here.
http://i.imgur.com/1IjGqPG.png
No error report and no log file.
Please let me know if you need anymore info.

Edit: Corrected my English.

[edge2054]

Looks like it can go below 0, actually adding damage to the last hit.