This new casting system is some kind of joke!
While casting it constantly gives me an error "<spell/skill> cannot be used now."
I have to wait 2/3 melee swings to be able to use skill/cast a spell again, while mob still hits me.
It's really destroys fun of gaming 
Please restor casting system like it was before patch 1.19.
Or at least look at this issue and fix it.
I beg of you!
As an evidence here is my log from 2 kills of a NM:
Code:
You defeat Old Six-arms.
You obtain a megalocrab leg.
Punishing Barbs set.
Slow set.
You summon Dexter.
You dismount Dexter.
Blizzard II cannot be used now.
Blizzard II cannot be used now.
Blizzard II cannot be used now.
Slow cannot be used now.
Slow cannot be used now.
Blizzard II cannot be used now.
Thunder II cannot be used now.
Blizzard II cannot be used now.
Blizzard II cannot be used now.
Blizzard II cannot be used now.
Blizzard II cannot be used now.
You defeat Gluttonous Gertrude.
You obtain a dodo feather.
You obtain a piece of dodo tenderloin.
You obtain a piece of dodo tenderloin.
You summon Dexter.
You dismount Dexter.
Blizzard II cannot be used now.
Profundity II cannot be used now.
Profundity II cannot be used now.
Blizzard II cannot be used now.
Thunder II cannot be used now.
Thunder II cannot be used now.
Thunder II cannot be used now.
Thunder II cannot be used now.
Thunder II cannot be used now.
Thunder II cannot be used now.
Profundity II cannot be used now.
Thunder II cannot be used now.
Stoneskin II cannot be used now.
Stoneskin II cannot be used now.
Thunder II cannot be used now.
Stoneskin II cannot be used now.
Stoneskin II cannot be used now.
Stoneskin II cannot be used now.
Stoneskin II cannot be used now.
Featherfoot cannot be used now.
Featherfoot cannot be used now.
Featherfoot cannot be used now.
Stoneskin II cannot be used now.
Stoneskin II cannot be used now.
Stoneskin II cannot be used now.
Stoneskin II cannot be used now.
Thunder II cannot be used now.
Thunder II cannot be used now.
You defeat Old Six-arms.