I've recently started getting very bizarre lag that I can't figure out what or who is the culprit. It started in Mid-December. I had not changed any settings on my computer, added any software or seen anything different from my ISP. It did NOT start following any specific patch.
Basically what happens is that I stop recieving all chat and battlespam. My group mates and the mobs stop swinging and health updates stop. BUT, they keep moving; that is, I'll see the melee continuing to re-position themselves. Finally, I'll see the mob turn as though it is fleeing, but still at the health % when the "lag" started. I'll then see my group mates all back away from the mob; one person kneel as though they are looting the still standing mob; and the puller go running off. Eventually, I'll get bombarded with updates and chat and the mob will go from very much alive to dead and looted in a matter of seconds. During this time, I'm able to cast but to no effect; turn on attack but not swing; or run around the zone and see mobs and other toons moving about. During this time, I see no difference in the framerate nor any change in the %.
So I'm clearly receiving some server updates (i.e. mob/toon locations and movement) but no chat, no melee updates, and no spell updates. I've talked with group members in Teamspeak during these "lag" periods and they are experiencing no such problems, and to them I've stopped all activity although my pet and my merc continue to fight and heal.
Some days, I get these "lag" spikes 2-3 times an hour. Sometimes I won't get them for several days. Any ideas as to what is causing this?