Thanalan graphics bug

Hello;
Evrytime I go in Thanalan, I have a bug in the graphics. It seems to be related to the distance (maybe drawing or fog). In the distance, I see black pixels flashing all over my screen. I didn't go to all zones to check it out but so far it only happens in Thanalan. I checked Black Shroud and La Coerthas and it doesn't occur there.
I tried updating DirectX and my graphic card drivers. I also played with the config of the game, but nothing helps.
I noticed the bug after last FFXIV update so I'm tempted to believe something went wrong when I installed/downloaded the patch.
Is there a way to reinstal a single patch?

Here is a screenshot:
http://i40.servimg.com/u/f40/11/80/54/66/ffxiv_10.jpg

Platform:
PC Athlon II x4 630 2.8Ghz with ATI Radeon HD 5770

ISP:
Belgacom

Type of Internet Connection:
DSL

Internet Connection Speed:
3Mbit/s

Date & Time:
Hard to tell exactly but I notriced it after the last game update

Frequency:
Everytime I go to Thanalan

Character Name:
Saburo Dawnfox

World:
Istory

Area and Coordinates:
All Thanalan region