I can relate to the OP (geez, look at how old this thread is

), and I used to by some replies occasionally on a different forum.
But I think being on a forum long enough can help. I think that when most members that annoy or offend you do that with a lot of other members, too. At least that has happened to me on another forum - and seeing that you're not the only one that has issues with a person that makes you nervous is a great relief.
What people get to know of you they most often get from forum posts alone, and that entitles no one to any sort of personal judgment. If other posters don't pertain to what you've
said but what they implicitly
assume about you, getting upset about it is a favor you don't have to do them. I think that people actually
can't really attack you personally, since they don't know you - which doesn't mean that's what some people are actually trying to do. But it doesn't work because in order to make a personal remark, you have to know the person.
Finally, it's written speech, and that alone can be the cause for a number of misunderstandings and misinterpretations (some of them intentional, but most of them probably not).