Crashing Issues Since 2.1

Issue:

I have experienced an issue wherein my client has crashed repeatedly, with increasing frequency, since the introduction of 2.1. With the last minor update, it has gotten to the point where I can't play more than 10 minutes at a time before a crash happens.

Crashes happen most often when changing areas, most notably in between the zones in Ul'dah, but not limited to them; teleporting also easily causes client crashing. I have also noticed a strange lag in my connection to the server whenever anyone nearby happens to begin crafting.

Troubleshooting I have attempted:

1. I have since uninstalled and reinstalled the game, as well as
2. tried different drivers for my graphics card, including installed a previous driver. This helped for a few days, but did not alleviate the issue entirely.
3. I have also since lowered the graphics in-game in an attempt to help, but to no avail.

Computer Information:

CPU: Intel Core i7-2600k
Memory: Corsair Vengeance 4GB DDR3 1600MHZ X4
GPU: NVIDIA GeForce GTX 670