I've noticed that Emacs.app opens up relative pathnames twice -- once for the actual file, and once for the relative pathname appended to the directory of the current buffer.
For example, trying to open by "a/b/text.txt" opens "a/b/text.txt" and attempts to open "a/b/a/b/text.txt".

I wonder if the following patch corrects the problem:

--- lisp/term/ns-win.el.orig    2010-12-12 23:31:04.000000000 -0500
+++ lisp/term/ns-win.el 2010-12-12 23:32:00.000000000 -0500
@@ -785,7 +785,7 @@
   "Do a `find-file' with the `ns-input-file' as argument."
   (interactive)
   (let ((f) (file) (bufwin1) (bufwin2))
-    (setq f (file-truename (car ns-input-file)))
+    (setq f (file-truename (expand-file-name (car ns-input-file) command-line-default-directory)))
     (setq ns-input-file (cdr ns-input-file))
     (setq file (find-file-noselect f))
     (setq bufwin1 (get-buffer-window file 'visible))

Here, the input filename is expanded according to the current working directory when Emacs was invoked.  Since I'm no expert, I don't know if this breaks something else.

Thanks for your time!