I don't generally dislike people because of threads or arguments. I may not like someone's behavior in a certain thread or may not like their opinions, but that generally doesn't translate to dislike of the person. Arguments on an internet forum just isn't usually enough information to base an opinion about a person on.
A pattern of behavior over a long period of time, maybe. And I'm sure there are "dealbreakers" so to speak, although I can't think of any at the moment. And I suppose if I just don't plain agree with someone on almost anything I wouldn't want to be their BFF or anything, but it doesn't mean I harbor any ill will, either.