--- a/piecrust/sources/base.py	Sat Nov 29 18:34:53 2014 -0800
+++ b/piecrust/sources/base.py	Sat Nov 29 20:51:30 2014 -0800
@@ -177,10 +177,12 @@
         if self._first_valid_path_index >= 0:
             return
         if self._first_valid_path_index == -1:
-            raise PageNotFoundError("No valid paths were found for page reference:" %
+            raise PageNotFoundError(
+                    "No valid paths were found for page reference: %s" %
                     self._page_ref)
 
         self._load()
+        self._first_valid_path_index = -1
         for i, path_info in enumerate(self._paths):
             if os.path.isfile(path_info[2]):
                 self._first_valid_path_index = i

--- a/tests/test_sources_base.py	Sat Nov 29 18:34:53 2014 -0800
+++ b/tests/test_sources_base.py	Sat Nov 29 20:51:30 2014 -0800
@@ -1,6 +1,7 @@
 import os
 import pytest
 from piecrust.app import PieCrust
+from piecrust.sources.base import PageRef, PageNotFoundError
 from .mockutil import mock_fs, mock_fs_scope
 
 
@@ -61,3 +62,83 @@
         actual = s.resolveRef(ref_path)
         assert actual == expected
 
+
+@pytest.mark.parametrize('page_ref, expected_source_name, expected_rel_path, '
+                         'expected_possible_paths', [
+        ('foo:one.md', 'foo', 'one.md',
+            ['foo/one.md']),
+        ('foo:two.md', 'foo', 'two.md',
+            ['foo/two.md']),
+        ('foo:two.html', 'foo', 'two.html',
+            ['foo/two.html']),
+        ('foo:two.%ext%', 'foo', 'two.html',
+            ['foo/two.html', 'foo/two.md', 'foo/two.textile']),
+        ('foo:subdir/four.md', 'foo', 'subdir/four.md',
+            ['foo/subdir/four.md']),
+        ('foo:subdir/four.%ext%', 'foo', 'subdir/four.md',
+            ['foo/subdir/four.html', 'foo/subdir/four.md',
+             'foo/subdir/four.textile']),
+        ('foo:three.md;bar:three.md', 'foo', 'three.md',
+            ['foo/three.md', 'bar/three.md']),
+        ('foo:three.%ext%;bar:three.%ext%', 'foo', 'three.md',
+            ['foo/three.html', 'foo/three.md', 'foo/three.textile',
+             'bar/three.html', 'bar/three.md', 'bar/three.textile']),
+        ('foo:special.md;bar:special.md', 'bar', 'special.md',
+            ['foo/special.md', 'bar/special.md'])
+        ])
+def test_page_ref(page_ref, expected_source_name, expected_rel_path,
+                  expected_possible_paths):
+    fs = (mock_fs()
+            .withConfig({
+                'site': {
+                    'sources': {
+                        'foo': {},
+                        'bar': {}
+                        }
+                    }
+                })
+            .withPage('foo/one.md')
+            .withPage('foo/two.md')
+            .withPage('foo/two.html')
+            .withPage('foo/three.md')
+            .withPage('foo/subdir/four.md')
+            .withPage('bar/three.md')
+            .withPage('bar/special.md'))
+    with mock_fs_scope(fs):
+        app = fs.getApp()
+        r = PageRef(app, page_ref)
+
+        assert r.possible_paths == [os.path.join(fs.path('/kitchen'), p)
+                                    for p in expected_possible_paths]
+
+        assert r.exists
+        assert r.source_name == expected_source_name
+        assert r.source == app.getSource(expected_source_name)
+        assert r.rel_path == expected_rel_path
+        assert r.path == fs.path(os.path.join(
+                'kitchen', expected_source_name, expected_rel_path))
+
+
+def test_page_ref_with_missing_source():
+    fs = mock_fs()
+    with mock_fs_scope(fs):
+        app = fs.getApp()
+        r = PageRef(app, 'whatever:doesnt_exist.md')
+        with pytest.raises(Exception):
+            r.possible_rel_paths
+
+
+def test_page_ref_with_missing_file():
+    fs = mock_fs()
+    with mock_fs_scope(fs):
+        app = fs.getApp()
+        r = PageRef(app, 'pages:doesnt_exist.%ext%')
+        assert r.possible_rel_paths == [
+                'doesnt_exist.html', 'doesnt_exist.md', 'doesnt_exist.textile']
+        assert r.source_name == 'pages'
+        with pytest.raises(PageNotFoundError):
+            r.rel_path
+        with pytest.raises(PageNotFoundError):
+            r.path
+        assert not r.exists
+