Cast speed and damage scaling

I might have found a bug while equipping a ring.
Without a ring my ice nova has 413.41 damage and 1.29 cast per second.
A ring with
9%elmental res
2 to 3 phy atk
17%increased cold damage
40 evasion rating
6 all attributes
18 int

reduces my damage to 400.9 and 1.21 cast per second.
Why would a ring that gives stats and damage reduce my ice nova damage and cast speed? Same for frost darts.

Yes, that was the problem. The life increase was so low, that i didn't even notice that i wasnt full life.
Thank you :)