Double-clicking the app doesn't work at all on Mac OSX 1.6.x.
Using the command line doesn't work either:
sage: notebook()

## /Applications/Sage-4.7.2-OSX-64bit-10.6.app/Contents/Resources/sage/sage: line 39: /Users/admin/.sage/local/bin/sage-sage: No such file or directory

ValueError Traceback (most recent call last)

/Users/admin/.sage/<ipython console=""> in <module>()

/Applications/Sage-4.7.2-OSX-64bit-10.6.app/Contents/Resources/sage/devel/sagenb/sagenb/notebook/notebook_object.pyc in __call__(self, *args, **kwds)
215 """
216 def __call__(self, *args, **kwds):
--> 217 return self.notebook(*args, **kwds)
218
219 notebook = run_notebook.notebook_twisted

/Applications/Sage-4.7.2-OSX-64bit-10.6.app/Contents/Resources/sage/devel/sagenb/sagenb/notebook/run_notebook.pyc in notebook_twisted(self, directory, port, interface, address, port_tries, secure, reset, accounts, require_login, server_pool, ulimit, timeout, open_viewer, sagetex_path, start_path, fork, quiet, subnets)
200 print '*' * 70
201
--> 202 nb = notebook.load_notebook(directory)
203
204 directory = nb._dir

/Applications/Sage-4.7.2-OSX-64bit-10.6.app/Contents/Resources/sage/devel/sagenb/sagenb/notebook/notebook.pyc in load_notebook(dir, interface, port, secure)
1807 # mainly to avoid circular references, etc. This also means
1808 # only one notebook can actually be used at any point.
-> 1809 import sagenb.notebook.twist
1810 sagenb.notebook.twist.notebook = nb
1811

/Applications/Sage-4.7.2-OSX-64bit-10.6.app/Contents/Resources/sage/devel/sagenb/sagenb/notebook/twist.py in <module>()
64 java_path = os.path.join(DATA)
65
---> 66 jsmath_image_fonts = is_package_installed("jsmath-image-fonts")
67
68 # the list of users waiting to register

/Applications/Sage-4.7.2-OSX-64bit-10.6.app/Contents/Resources/sage/local/lib/python2.6/site-packages/sage/misc/package.pyc in is_package_installed(package)
168 True
169 """
--> 170 return any(p.startswith(package) for p in install_package())
171
172 def standard_packages():

/Applications/Sage-4.7.2-OSX-64bit-10.6.app/Contents/Resources/sage/local/lib/python2.6/site-packages/sage/misc/package.pyc in install_package(package, force)
125 if __installed_packages is None:
126 X = os.popen('sage -f').read().split('\n')
--> 127 i = X.index('Currently installed packages:')
128 X = [Y for Y in X[i+1:] if Y != '']
129 X.sort()

ValueError: list.index(x): x not in list