The THM/BLMs repertoire of spells consists of 2 instant cast spells, Blizzara and Thundara. While running or standing still, I can cast Blizzara and it will instantly activate, as it should. Thundara however, will not if subtargetting is switched to on. I doubt this is how it is suppose to function considering in one mode, there is a clear advantage to the other.

ISP:
Comcast

Type of Internet Connection:
Cable

Internet Connection Speed:
30 Mbit/s Download, 3 Mbits/s Upload

Date & Time:
Constant, all times.

Frequency:
Always with subtargetting on.

Character Name:
Shanoa Kikosho

Race:
Elezen F

World:
Rabanastre/Durandal

Class/Level:
50 THM/50 BLM

Area and Coordinates:
All areas with enemies.

Party or Solo:
Party and Solo. Party with 1-8 members.

Monster Name:
All target-able monsters.

In-Game Time:
Anytime.

Steps:
1: Turn off subtargetting with /subtarget off.
2: Target monster and proceed to cast Thundara while running. The spell instantly activates and the monster is damaged.
3: Turn subtargetting back on with /subtarget on.
4: Target monster and proceed to cast Thundara while running. Thundara fails to activate and I receive the message, "You cannot cast spells while moving."