Maryz - as I said earlier, it depends entirely on the situation.
there have been a few threads where info just really has to be corrected.
others, yes, it is just down to a difference of opinion/change of heart.
I guess it all depends on how much the thread/subject means to you.
i don't usually get involved at all, apart form on vax threads, or some SN subjects (and it is usually correcting SN misinformation where I will not let go - not to the extent of stalking or PMing, obviously
)
hypothetically speaking, I could see a situation where, eg if a poster I had always been in agreement with (on a SN issue, say) suddenly started argumentatively (and erroneously imo) putting the opposite case, I might PM and say "is everythign ok, only oyu used ot think abc, not xyz". and as I said earlier, I would be expecting a "oh fuck off" reply, or a continuation of the discussion.
I don't see the point in always walking away (which is not ot say that I htink everyhting should be doggedly pursued to the last word, each and every time). surely we are all here for discussion/debate/friendly argument? not just to each babble away disjointedly, with no answers?