Oh neat, a flame war, can I play too? :-) While I don't know (or care to read) where this little war started from (though I can guess from the topic), I'd like to chime in about the topic at hand.
exist:
http://dictionary.reference.com/search?q=exist
"To have actual being; be real."
know:
http://dictionary.reference.com/search?q=know
"To perceive directly; grasp in the mind with clarity or certainty."
There is a difference between a thing and knowledge of the thing. While common usage can cause the definitions of these two to cross, a quick check of the dictionary shows how they differ.
Finally, I think there's little point in arguing words; words are simply meant to communicate thoughts, so just agree on a meaning of the words and move on to the underlying thoughts (which are apparently lost in the 90+ Messages preceding this.).
-Jeff