diff --git a/src/calibre/ebooks/mobi/output.py b/src/calibre/ebooks/mobi/output.py
index 2035df261a..c8fe87a161 100644
--- a/src/calibre/ebooks/mobi/output.py
+++ b/src/calibre/ebooks/mobi/output.py
@@ -40,7 +40,7 @@ class MOBIOutput(OutputFormatPlugin):
 
     def check_for_periodical(self):
         if self.oeb.metadata.publication_type and \
-            self.oeb.metadata.publication_type[0].startswith('periodical:'):
+            unicode(self.oeb.metadata.publication_type[0]).startswith('periodical:'):
                 self.periodicalize_toc()
                 self.check_for_masthead()
                 self.opts.mobi_periodical = True
@@ -54,7 +54,7 @@ class MOBIOutput(OutputFormatPlugin):
                 found = True
                 break
         if not found:
-            self.oeb.debug('No masthead found, generating default one...')
+            self.oeb.log.debug('No masthead found, generating default one...')
             from calibre.resources import server_resources
             try:
                 from PIL import Image as PILImage
@@ -84,12 +84,16 @@ class MOBIOutput(OutputFormatPlugin):
                     sections[0].append(x)
             else:
                 sections = list(toc)
+                for x in sections:
+                    x.klass = 'section'
             for sec in sections:
                 articles[id(sec)] = []
                 for a in list(sec):
+                    a.klass = 'article'
                     articles[id(sec)].append(a)
                     sec.nodes.remove(a)
-            root = TOC(klass='periodical', title=self.oeb.metadata.title[0])
+            root = TOC(klass='periodical',
+                    title=unicode(self.oeb.metadata.title[0]))
             for s in sections:
                 if articles[id(s)]:
                     for a in articles[id(s)]:
diff --git a/src/calibre/ebooks/mobi/writer.py b/src/calibre/ebooks/mobi/writer.py
index 7e5bb77460..b8b5c8f796 100644
--- a/src/calibre/ebooks/mobi/writer.py
+++ b/src/calibre/ebooks/mobi/writer.py
@@ -1820,7 +1820,6 @@ class MobiWriter(object):
         # Process 'periodical', 'section' and 'article'
         if node.klass is None :
             return
-
         t = node.title if title is None else title
         t = self._clean_text_value(t)
         self._last_toc_entry = t
@@ -1982,7 +1981,7 @@ class MobiWriter(object):
         elif self._periodicalCount and self._sectionCount > 1 :
             pt = None
             if self._oeb.metadata.publication_type:
-                x = self._oeb.metadata.publication_type[0].split(':')
+                x = unicode(self._oeb.metadata.publication_type[0]).split(':')
                 if len(x) > 1:
                     pt = x[1]
             mobiType = {'newspaper':0x101}.get(pt, 0x103)
diff --git a/src/calibre/ebooks/oeb/base.py b/src/calibre/ebooks/oeb/base.py
index 86c0ae1ed6..acf95df502 100644
--- a/src/calibre/ebooks/oeb/base.py
+++ b/src/calibre/ebooks/oeb/base.py
@@ -47,7 +47,7 @@ XPNSMAP      = {'h'  : XHTML_NS, 'o1' : OPF1_NS,    'o2' : OPF2_NS,
                 'd09': DC09_NS,  'd10': DC10_NS,    'd11': DC11_NS,
                 'xsi': XSI_NS,   'dt' : DCTERMS_NS, 'ncx': NCX_NS,
                 'svg': SVG_NS,   'xl' : XLINK_NS,   're': RE_NS,
-                'mbp': MBP_NS }
+                'mbp': MBP_NS, 'calibre': CALIBRE_NS }
 
 OPF1_NSMAP   = {'dc': DC11_NS, 'oebpackage': OPF1_NS}
 OPF2_NSMAP   = {'opf': OPF2_NS, 'dc': DC11_NS, 'dcterms': DCTERMS_NS,