--- a/hgext/transplant.py	Mon Apr 04 16:21:57 2011 -0500
+++ b/hgext/transplant.py	Mon Apr 04 16:21:59 2011 -0500
@@ -237,7 +237,7 @@
                 seriespath = os.path.join(self.path, 'series')
                 if os.path.exists(seriespath):
                     os.unlink(seriespath)
-                p1 = repo.dirstate.parents()[0]
+                p1 = repo.dirstate.p1()
                 p2 = node
                 self.log(user, date, message, p1, p2, merge=merge)
                 self.ui.write(str(inst) + '\n')