Platform: Windows 7 x64
ISP: Comcast
Type of Internet Connection: Cable
Internet Connection Speed: 20mbit down, .75mbit up
Date & Time: 8/02/2011 around 12:38 AM Pacific Standard Time.
Frequency: Always, Happens every time.
Character Name: Liquid Snake
Race: Lalafell
World: Wutai
Class/Skill Rank: 17 Murauder/14 Lancer
Physical Level: 20
Area and Coordinates: Upper Tailor Row, Ul'dah Market Ward (and all other markets)
Party or Solo: Solo
NPC Name: None
Monster Name: None
In-Game Time: Don't know
Steps:
1. Try to create retainer
2. Get stuck forever while the NPC is never summoned, nor getting an error message about there are too many retainers in the area
3. even in other cities when I try to create a retainer I get the black screen and it just hangs.

I can fix it by alt-f4ing out of the game, but /logout, other actions, etc., do not work. I get stuck in place until I force logout. Once I log back on, I can move and do everything else as normal again.