I think it has something to do with the spawn rate created by the share party, I am not sure if it is my computer or Joymax but I have a similar situation.
My computer isn't that crappy. What I mean is maybe the programing is written in an inefficient manner causing anything but ultra high end machines to lag.
This weekend though I had weird bad lag when in the caves or on the ice. Only certain locations caused lag. Couldn't grind or even powerlvl my euro
