Is M. J. right? Does it matter if you're black or white?

So I'm in the break room this afternoon at lunch with 3 of my co-workers engaging in the usually lunchtime banter: food, family, weekend plans, sports. One of the girls starts talking about how she is so annoyed by the recent publicity the Bears and Colts coaches have received because they're the first two black coaches to go to the Super bowl at the same time. I mean really-- who cares if there have never been two black people in LEADERSHIP in an industry COMPLETELY fueled by blacks in the year 2007. Hmm... sounds like a familiar economic system that was once completely fueled by blacks with whites in leadership. At least this time we can become millionaires-- lest we run the damn thing. I digress.
So the conversation continues and we (my self and two other girls) try to explain the importance of recognizing historical moments in a particular ethnic community (i.e. Halle Berry and Denzel Washington, Colin Powell, Condoleezza Rice- you get the point)
I made the horrible mistake of saying the phrase "cracker jack" in reference to the lily white(I am allowed to say that- no?) community that I live in. My co-worker, the same girl who feels like "the media is shoving the fact that two black coaches are going to the Super Bowl in her face" was offended. She quickly corrected me and the conversation, needless to say, took a turn down Gray Street.
She explained to me that the word cracker is offensive to white people and that she doesn't even like when people call her white because she is Caucasian.
She then took a leap, and I mean S--T--R--E--T--C--H and said it would be the same as her using the word Nigger. Enter Krystal stage left.
I (being the civil soul that I am) quickly apologized for the "offensive" comment that I made, noting that I realize it is derogatory but that I was not aware that ANYONE saw it as comparable to the word Nigger.
I submit- I got comfortable and loss my head and said Cracker in front of 3 white women. Krystal- don't do that. HOWEVER, I DID let her know that the meaning, connotation, origin, level of offense, WHATEVER-- is NOT the same.
The conversation ended and an hour later we all trotted back to our cubes. Then a few hours later I receive an email(http://www.adversity.net/special/niggardly_terms.htm)
An attempt to educate me I propose. And to point out the fact that the word Cracker is derogatory. Point Taken.... My point also made.
The definition of the word Cracker
Derogatory reference to whites, typically conservative southerners who are still fighting the Civil War; term may or may not connote a belief in segregation or slavery. Used mostly by blacks and by liberal, white northerners.
Another co-worker sent this:
http://gyral.blackshell.com/names.html
The definition of the word Cracker:
First used by the slaves to refer to their slave owners. Could originate from a) 'corncracker,' someone who distills corn whiskey, or b) the 'crack' of a whip the slave owners used or c) "white as a soda cracker". Might also refer to southern farmers too poor to own slaves, so they had to work their own fields. Cracker was a derogatory term used by the Scarlett O'Hara set.
I thought to my self... well damn. That word IS offensive. It just MAY be as offensive as the word Nigger.
I mean really, who would want to be associated with a term defined by the sound an object made when it sliced the back of a black person.
CRACKer goes the whip.