The order in which people get the PL bug / insta LD (both seem to be the same thing, and I can't identify any indicator as to which you'll get before it happens) seems to be the same as the order in which they entered the zone. In general it seems to happen after a certain amount of time in the zone as well. When it does occur, it seems to me to generally be about 90 minutes after entering. You seem to be able to reset your timer by zoning or relogging, but a couple times it has felt like that didn't work. This is all based on casual observation, though; I haven't done any timing or recording of information.
In Venerate we refer to it as the AIDS of SoD--once one person gets it, it spreads like mad, generally to the people who are cybering with Tapein (specifically, everyone).
There are exceptions to the usual timing, such as in the NE corner of Red Sun Mines, where first the ping goes crazy (refreshing several times a second, rather than the usual every couple of seconds), sometimes lag shoots up, and then everyone gets PL bugged or LDs. In this particular area it seems to occur about every 3-10 minutes, and can be prevented if *everyone* affected relogs. If the first person to log out gets back in before the last person is out, it remains.
I know Maimai speculated that it might be related to the bridges over the lava along the eastern edge of the zone. I have no idea whether that's the case, but you don't seem to have to be within sight of them or anything of the sort. I could also imagine it being something along the lines of the switches (disabled here, but active in Live) for the doors in the fortress, or the one bridge a bit farther west that is "locked" (was lowered by another switch on Live, which is now disabled).
D all of us do, but... is there any way some of these bugs can be addressed, like the group bug, tell bug.. and A LOT more server stablity would be freakin awesome
