What steps will reproduce the problem?
1. Create a macro with a modifier example:
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#showtooltip
/cast [mod] Crusader Strike; Holy Shock
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2. Create a Power Aura which triggers when "Action Usable", for example: Light's Hammer.
3. Engage in Combat, Use Light's Hammer to let it go on Cooldown.
4. Click on a modifier key to activate the macro's modifier version.
5. Power Aura's will trigger the "Action Usable" - Light's Hammer prematurely.

What is the expected output? What do you see instead?
"Action Useable" auras should only trigger when the action is useable, i.e. comes off cooldown or procced; however, as the modifier key is pressed, Power Aura prematurely triggers the "Action Usable" auras.  This becomes very misleading and potentially leads to blowing a global cooldown due to a misclick.  

What version of the product are you using?
4.27.6

Do you have an error log of what happened?
No, no error is generated.

Please provide any additional information below.
This has been reported before and seems to have returned.
http://wow.curseforge.com/addons/powerauras-classic/tickets/207-macro-modifier-key-causes-aura-event-prematurely/