--- /root/posixpath.py	2009-08-22 09:05:09.000000000 -0700
+++ /root/posixpath.py	2009-08-22 09:00:52.000000000 -0700
@@ -62,6 +62,8 @@ 
     will be discarded."""
     path = a
     for b in p:
+        if b == None:
+            continue
         if b.startswith('/'):
             path = b
         elif path == '' or path.endswith('/'):