Aetherflow does not give any stacks when used despite the CD timer starting.

I know this has happened at least twice, maybe three times, but the first few times I just assumed I was going crazy lol.

ISP:
CableOne

Type of Internet Connection:
cable

Internet Connection Speed:
good

Date & Time:
2/13/2014 ~11:45 CST

Frequency:
Twice

Character Name:
Mitth Rawn

Race:
Hyur Highlander

World:
Ultros

Class/Level:
Lv46 SCH

Area and Coordinates:
Isles of Umbra; Ship Graveyard (x12,y36)

Party or Solo:
Solo

NPC Name:
None

Monster Name:
Lammergeyer

In-Game Time:
unknown

Steps:
I engaged the mob, applied Miasma I & II and Bio I & II. Cast Ruin II+Energy Drain in one GCD; Ruin+Energy Drain in one GCD quickly followed by Aetherflow as I was out of stacks. At this point I received no stacks but the CD timer on Aetherflow began.

This is with no macros or clicking of abilities, just key-binding.

I know this has happen at least once before in Stone Vigil and during a Fate Party, all in the last week or so but I don't have enough info on those. I haven't noticed this until recently.