My client seems to lock up when I enter many sections of the game that feature "jungle" style terrain. Particularly The Captives, but also Where There's Smoke or Gladewatch, I start getting huge lag spikes that make the game unplayable. Bad enough that it's hard to type coherently, or even access the menu to quit the game.
I've not had any problems with other quests, like Kobold Assault... never gives me any problems, despite the similar terrain style.
I've recently reinstalled the game, and that didn't seem to help.
I've tried running the game on very low graphical settings, and that didn't help, either.
Previously, I'd been having some issues with video drivers, and I thought that was hammered out fairly effectively, as the game runs smoothly when not having the above described problem. However, the symptoms are... well, similar. The horrible lag will often be accompanied by severe graphical errors after I come out of the lag.
When this happens, the lag and graphical errors will persist after I leave the area and go back to town. However, if I log out and return, the problem is usually gone unless I enter a problem area again.
Any idea why this might be happening?
(Edited for clarity, and to add some key information that I later thought of.)