The (Not So) Quiet Anger of a Colleague

I have not been a teacher very long. I admit that I am a rookie. However, it has not taken very much time for me to make friends and enemies. Unfortunately, in my second month of student teaching I was told by another teacher that she hated me. She flat out did not like me, what I stood for, or what I taught. Honestly this was a shock. I could not believe that this woman, a fellow teacher, was taking time to explain to me why she hated me. At first, I thought it was a joke, so I laughed. I figured out it was not a joke when she cocked her head like a puppy hearing a noise and asked, "and just WHAT is so funny?"
Fast forward to today. I was covering a class when I saw this colleague in the hall. She stopped, turned to me, and said, "What are you doing here?" I responded, "I'm covering this class." After taking in the room, the students, and myself, she took a deep breath and asked, "But why you?"
Now, how would you answer that? Would you flip her off? Tell her to stuff it? Answer politely? Regardless of your answer, I was actually polite (a strain, but I did it). I told her, "They asked me to cover, I had the free time, so I said yes." Again, she hit me with that look. She was unhappy with me being in the building.
Confused, I turned to the class to begin. One student quickly said, "Mr. L. She really doesn't like you." Well, I already knew that, but I didn't want to be unprofessional, so I said, "I guess." However, this student was not done. "No, Mr. L, I don't think you understand. We mentioned you in her class, and she went nuts. She said you were a horrible teacher, a horrible person, and we should never take a class with you." This sounded too much like a joke, so I laughed it off, but then another student said it was true. I knew I annoyed people, but I never realized that one conversation (and we had only ONE conversation) was enough to make someone talk smack about you to students. Still, that's so unprofessional. You do not go to the students and talk down about another teacher. That takes away respect and is classless. Still, this was out of the mouth of high school students. I just wasn't sure it could be the truth. Let me explain: I respect and like my students, but sometimes I think they like to stir up the hornets' nest.
Unsure of whether or not the truth had been told, I turned to one of the faculty members that I knew always told it as it really is. He has no problem telling students what they may not want to here. He has never backed down from putting faculty members in their place. I asked him if this woman had really said these things. He took a breath, looked at me, and said, "Yup. She hates you. She hates the fact that you don't share her beliefs, and apparently she really doesn't like that you give the students any control in the class."
So what does that say for the professionalism of teachers? Is her anger toward me such that instead of talking just to me about it, she has to get the students involved? Is she hoping that the students will turn on me and lead a coup within my classroom? That she can come to my room, and my head will be on a pike, and the students will be shouting her name? I just don't get it.
In the end, however, I care more about the students than what one of my colleagues thinks of me. She doesn't really affect my job. The students do. If my students are not doing well, then I am not doing well. That's the point of being an educator: to better the students, not the faculty. Perhaps this teacher has forgotten that.