diff --git a/pygal/config.py b/pygal/config.py
index 0fd2410..bf8923d 100644
--- a/pygal/config.py
+++ b/pygal/config.py
@@ -40,12 +40,12 @@ class Config(object):
     #: Display values in logarithmic scale
     logarithmic = False
     #: List of css file, can be an absolute file path or an external link
-    css = ['style.css', 'graph.css']  # Relative path to pygal css
+    css = ('style.css', 'graph.css')  # Relative path to pygal css
     #: List of js file, can be a filepath or an external link
-    js = [
+    js = (
         'https://raw.github.com/Kozea/pygal.js/master/svg.jquery.js',
         'https://raw.github.com/Kozea/pygal.js/master/pygal-tooltips.js'
-    ]
+    )
     #: Style holding values injected in css
     style = DefaultStyle
     #: Various font sizes
@@ -105,6 +105,8 @@ class Config(object):
 
     def __init__(self, **kwargs):
         """Can be instanciated with config kwargs"""
+        self.css = list(self.css)
+        self.js = list(self.js)
         self.__dict__.update(kwargs)
 
     def __call__(self, **kwargs):
diff --git a/pygal/css/base.css b/pygal/css/base.css
index 5391838..d79efd4 100644
--- a/pygal/css/base.css
+++ b/pygal/css/base.css
@@ -23,7 +23,7 @@
  */
 
 .title {
-  font-family: monospace;
+  font-family: sans;
   font-size: {{ font_sizes.title }};
 }
 
diff --git a/pygal/css/graph.css b/pygal/css/graph.css
index 6e65b12..d5174aa 100644
--- a/pygal/css/graph.css
+++ b/pygal/css/graph.css
@@ -22,7 +22,7 @@ text.no_data {
   text-anchor: middle;
 }
 
-.line {
+.guide.line {
   fill-opacity: 0;
 }
 
diff --git a/pygal/graph/base.py b/pygal/graph/base.py
index 9fa7f94..6ee0442 100644
--- a/pygal/graph/base.py
+++ b/pygal/graph/base.py
@@ -54,7 +54,7 @@ class BaseGraph(object):
     def add(self, title, values):
         """Add a serie to this graph"""
         self.series.append(
-            Serie(title, list(values), len(self.series), self.__value__))
+            Serie(title, values, len(self.series), self.__value__))
 
     def reinit(self):
         """(Re-)Init the graph"""
diff --git a/pygal/graph/dot.py b/pygal/graph/dot.py
index ada637d..207c803 100644
--- a/pygal/graph/dot.py
+++ b/pygal/graph/dot.py
@@ -62,7 +62,7 @@ class Dot(Graph):
         self._box.ymax = y_len
 
         x_pos = [n / 2 for n in range(1, 2 * x_len, 2)]
-        y_pos = [n / 2 for n in range(1, 2 * y_len, 2)]
+        y_pos = [n / 2 for n in reversed(range(1, 2 * y_len, 2))]
 
         for j, serie in enumerate(self.series):
             serie.points = [
diff --git a/pygal/graph/xy.py b/pygal/graph/xy.py
index 80d280e..a803e91 100644
--- a/pygal/graph/xy.py
+++ b/pygal/graph/xy.py
@@ -33,6 +33,11 @@ class XY(Line):
         return 'x=%s, y=%s' % tuple(map(self._format, values[i]))
 
     def _compute(self):
+        for serie in self.series:
+            for metadata in serie.metadata:
+                if not hasattr(metadata.value, '__iter__'):
+                    metadata.value = (metadata.value, self.zero)
+
         xvals = [val[0]
                  for serie in self.series
                  for val in serie.values
diff --git a/pygal/test/test_graph.py b/pygal/test/test_graph.py
index 88309e9..72e867b 100644
--- a/pygal/test/test_graph.py
+++ b/pygal/test/test_graph.py
@@ -62,6 +62,12 @@ def test_render_to_png(Chart, datas):
     os.remove(file_name)
 
 
+def test_simple_value(Chart):
+    chart = Chart()
+    chart.add('uni-value', 1)
+    assert chart.render()
+
+
 def test_metadata(Chart):
     chart = Chart()
     v = range(7)
diff --git a/pygal/util.py b/pygal/util.py
index 5c3cc70..3924cbc 100644
--- a/pygal/util.py
+++ b/pygal/util.py
@@ -196,7 +196,7 @@ def decorate(svg, node, metadata):
     if hasattr(metadata, 'xlink'):
         xlink = metadata.xlink
         if not isinstance(xlink, dict):
-            xlink = {'href': xlink}
+            xlink = {'href': xlink, 'target': '_blank'}
         node = svg.node(node, 'a', **xlink)
     for key in dir(metadata):
         if key not in ('value') and not key.startswith('_'):