I had the same problem. It was in the quest instance, after completing the requirements for it. Trying to speak to Pascaleret caused the game to freeze most functions. Received no errors, but had to exit the window. I didn't try typing /logout command, but it happened again after logging in and attempting to talk to him again.

Windows 7 pro 64 bit
DSL broadband
18Mbs
Around 6:30 p.m. CST 3/7/11
Happened twice, avoided him after third log in to finish quest
Biti Aotu
Miqo'te
Besaid
Rank 30 Archer
Physical 31 if I remember correctly
Owl's Nest
Solo