Found.

Found it. And found that the version in my text is DIFFERENT! Gasp!

Corwin version, as I will forever remember it... also known as the version I found online after getting the hints from Amber:

"Oh what can ail thee, knight-at-arms,
Alone and palely loitering?"

Text version:

"Ah, what can ail thee, wretched wight,
Alone and palely lotering;"

Corwin version:

"For sidelong would she bend, and sing
A faery's song."

Text version:

"For sideways she would lean, and sing
A fairy's song."

Corwin version:

"She took me to her elfin grot,
And there she wept and sighed full sore,
And there I shut her wild eyes
With kisses four."

Text version:

"She took me to her elfin grot,
And there she gaz'd and sighed deep,
And there I shut her wild sad eyes--
So kiss'd to sleep."

So
anyway. I want to put this in my paper... but it's already long enough
and doesn't exactly follow my thesis as straightly as I'd like, because
I diverge about how DAMN COOL it is to go look up all the old meanings
of the words and what they might possibly mean in context... so I don't
think I should add more about a differing version ^^;;

Amber is STILL feckin' awesome for alluding to this.