Arrive "at a knowledge" or "at knowledge: Qual utilizar

This thread at the Jogo das Palavras section of the forum clearly states knowledge an uncountable word, thus it doesn't take an article. To my own dismay, though, I Googled many constructions of the "at a knowledge" type.

This left me wondering why it takes an article in "arrive at a knowledge." My original copy of MS-Word 2007 says no, it doesn't. Does your word processor say yes, it does?