Sometimes splitting threads would be good, now the other thread is talking about windmills instead of the actual the other topic <img src="http://www.catsailor.com/forums/images/graemlins/wink.gif" alt="" />.
I don't see any problem with that. Let the thread be dynamic and flow. No need for strict structure. You never know where the discussion could end up, but moving from Wayne's frustrations about internet muppets, to 3DL sails to windmills is a bit extreme though.