diff -urN mapnik-v2.0.1.old/SConstruct mapnik-v2.0.1/SConstruct
--- mapnik-v2.0.1.old/SConstruct	2012-05-26 11:04:50.364638533 +0200
+++ mapnik-v2.0.1/SConstruct	2012-05-26 11:07:49.554621727 +0200
@@ -501,16 +501,7 @@
         #print 'missing opt', opt
         preconfigured = False
 
-# if custom arguments are supplied make sure to accept them
-if opts.args:
-    # since we have custom arguments update environment with all opts to 
-    # make sure to absorb the custom ones
-    opts.Update(env)
-    # now since we've got custom arguments we'll disregard any 
-    # pickled environment and force another configuration
-    preconfigured = False
-
-elif preconfigured:
+if preconfigured:
     if not HELP_REQUESTED:
         color_print(4,'Using previous successful configuration...')
         color_print(4,'Re-configure by running "python scons/scons.py configure".')