Youtube Videos Stop Characters From Rendering

[Hinabi]

Details:
While playing FFXI in windowed mode, should I launch my web browser and play a video on www.youtube.com, all characters on screen will disappear and become untargetable. No characters render from this point on. This applies to PCs, NPCs, doors, FOV books, monsters, etc.

Closing my browser and proceeding to change zones does not help. Closing my browser and logging out and back in sometimes helps. I usually have to restart POL.

<edit>
If I log out after this has happened and switch characters, targets will not render for the second character either
</edit>

Sidenote: People are still able to target/check/browse me. I can still see my character.

Frequency:
It happens anytime I play a video. Regardless of what zone I'm in or the video I play.

Platform:
PC

PC Manufacturer & Model Number:
2008 MacBook Pro

Operating System:
Windows XP SP3 via Bootcamp

Graphics Card:
NVIDIA GeForce 8600M GT

ISP:
AT&T Uverse

Type of Internet Connection:
DSL

Web Browser
Firefox 3.6.13