Pointing out a troll's spelling and grammar mistakes isn't an effective counter for relatively cool-headed trolls. If someone pulls a MaxPayne, on the other hand...
And while we're at it, my philosophy is that spelling on a message board should be perfect or near perfect (the net is at your disposal, ladies and gentleman-- use it!), and there should be very few-- if any-- typos (take some time to READ OVER your posts, people). I suppose bad grammar's forgivable, since that's much more dependent on your English proficiency.
P.S. - Sorry for singling you out, Max. :-)