I love my job and what I do and I've been at it a little more than a year and a half. This was also my first IT position. It's (almost) perfect for me.
In my company there's several smaller satellite offices and the corporate office. I'm the 2nd tier support guy at the corporate office so when the helpdesk can't fix things over the phone or VNC / Shadow I get to go take care of it. My situation is completely the opposite from what you've described. I've always gotten nothing but respect and admiration. People look up to me for the solution to their every computer problem. "Matt can fix it" is the solution to just about everything that goes wrong that involves a computer. I think I've made myself too indispensable.
Alas, here's where I encounter dissatisfaction with my job: I'm always getting compliments but it doesn't always have anything to do with my work. Sometimes its about my appearance or my clothing or the cologne I happened to be wearing that day. [for this reason I stopped wearing fragrances to work altogether] Unfortunately for me, some of the older women tend to lay on the compliments WAY too thick... It's disgusting. I think my problem is I'm just too good looking for what I do. I KNOW that sounds conceited but how else do you explain this one; I overheard some women at lunch talking about who the hottest guy in the building was. Two names were mentioned and the unanimous vote was me. Yeah. I didn't need to hear that from someone who's old enough to be my grandmother. And I don't think that good looking, just maybe a little better than average, or just "work hot"... if you don't know what that means it's on urban dictionary.
Maybe your problem is that people don't like something about you as a person and regardless of how nice you act toward them, you're going to offend. I work with other guys that seriously irritate me to the point that I act like a total dick to them just so they'll stay the f*ck away from me. One guy talks WAY too loud and his breath smells like he had a sh*t sandwich for lunch. The other guy has this anoying nasal drip and sits about 20 feet away from my desk snorting back the phlegm that drips down the back of his throat from his sinuses. Every 30 seconds or so you can hear him horking it back. It got so bad that I actually got up and shut my door today so I wouldn't have to listen to it. That says absolutely nothing about their skills as IT guys or their personalities. If it wasn't for those things that irritate the crap out of me, then I wouldn't put up the asshole facade.
Something to think about.