yeah it's supposed to be "a unique".
"A Unique or An Unique?
Just another note about the challenges of the English language. Why "a unique..." rather than "an unique..."? When a "u" word is pronounced as though it begins with a "y" (yoo nique), it's treated more like the consonant sound of the y. So, a university, an umbrella, a usual day, an unusual day."
from:
http://wordwhirled.blogspot.com/2005...or-unique.html
xD