I'm having the exact same problem. I've followed the sticky on sun java, scaned for adware, spyware, viruses, worms and trojens, but I still have the lagg. It doesn't matter what world I log in to or if I have something else running in the background. The lag gets really bad when every I move my character to an area that has other player or npc. I've been dealing with this for about a week and I'm starting to think its something with rs and not my comp because there isn't much else I can do.