We should look in the directory containing the module, not in the module itself, when we're looking for the resource file.
diff --git a/Mac/Lib/macresource.py b/Mac/Lib/macresource.py
index 9b442a8..001e6cc 100644
--- a/Mac/Lib/macresource.py
+++ b/Mac/Lib/macresource.py
@@ -49,7 +49,7 @@
 	if sys.modules.has_key(modname):
 		mod = sys.modules[modname]
 		if hasattr(mod, '__file__'):
-			searchdirs = [mod.__file__]
+			searchdirs = [os.path.split(mod.__file__)[0]]
 	if not searchdirs:
 		searchdirs = sys.path