Grid Over head light glitching

[DoomCky]

Platform: Win 7 64 bit
GPU: GeForce GTS 240 Driver: 285.62 ( but since the start of game it has happened so its not the driver. )
ISP: RCN
Type of Internet Connection: Cable
Internet Connection Speed: 60 MBs/6MBs
Date & Time: Anytime
Frequency: Always
Character Name: Doom Cky
Race: Hume
World: Besaid
Class/Skill Rank: All
Area and Coordinates: Gridania (7, 5)/ (7, 3)/ (6, 2)/ (5, 2)/ (4, 4)/ (5, 5)
In-Game Time: Anytime
Steps:
1.Walk around town
2. Anywhere there are over head canupys look at the orange lights
3. At the part the brownish thing connects to the orange ball there is a glitch in graphics. look liek a cliping issue where orange ball is tryign to come though the brown thing
4. When you stop moving it won't happen
5. Not all lights do it: the ones leaving town on the east side don't do it.