Index: pkg_resources.py
===================================================================
--- pkg_resources.py	(revision 42230)
+++ pkg_resources.py	(working copy)
@@ -142,20 +142,22 @@
     XXX Currently this is the same as ``distutils.util.get_platform()``, but it
     needs some hacks for Linux and Mac OS X.
     """
-    if sys.platform == "darwin":
+    from distutils.util import get_platform
+    platform = get_platform()
+    # The Python 2.4.2 universal build knows better, ensure that this isn't
+    # already done
+    if sys.platform == "darwin" and platform.startswith('darwin-'):
         try:
             version = _macosx_vers()
             machine = os.uname()[4].replace(" ", "_")
-            return "macosx-%d.%d-%s" % (int(version[0]), int(version[1]),
+            platform = "macosx-%d.%d-%s" % (int(version[0]), int(version[1]),
                 _macosx_arch(machine))
         except ValueError:
             # if someone is running a non-Mac darwin system, this will fall
             # through to the default implementation
             pass
+    return platform
 
-    from distutils.util import get_platform
-    return get_platform()
-
 macosVersionString = re.compile(r"macosx-(\d+)\.(\d+)-(.*)")
 darwinVersionString = re.compile(r"darwin-(\d+)\.(\d+)\.(\d+)-(.*)")