Another thread on the issue, which is also in the in-game bugs section:

http://forum.square-enix.com/ffxiv/t...ight=Linkshell

As the poster at the bottom said, this is a somewhat isolated issue.. so please provide as much specific information as possible for us to make some sort of diagnosis.

You may find an information template here:
http://forum.square-enix.com/ffxiv/t...hnical-Support!

Open FFXIV config, choose System, then Copy to clipboard. Post your system information for us in this thread.