[OS X Emacs] emacsclient with aquamacs: error opening socket

[Oz Linden (Scott Lawrence)]

I'm trying to use Aquamacs as an emacs server on MacOS 10.6, but when I 
invoke it I get this error:

emacsclient: error accessing server file "/Users/oz/.emacs.d/server"

That file is a socket, and appears to match what the server is creating 
(if I delete it and then launch Aquamacs or run server-start in a 
running Aquamacs, it reappears).

I have run the install of command line tools, and the emacsclient I'm 
running is the one that it put into /usr/bin

Suggestions on how to debug this?