diff --git a/src/calibre/ebooks/mobi/reader.py b/src/calibre/ebooks/mobi/reader.py
index 6811f9ccda..8b81702bc1 100644
--- a/src/calibre/ebooks/mobi/reader.py
+++ b/src/calibre/ebooks/mobi/reader.py
@@ -308,8 +308,8 @@ class MobiReader(object):
             if 'filepos-id' in attrib:
                 attrib['id'] = attrib.pop('filepos-id')
             if 'filepos' in attrib:
-                filepos = int(attrib.pop('filepos'))
-                attrib['href'] = "#filepos%d" % filepos
+                filepos = attrib.pop('filepos')
+                attrib['href'] = "#filepos%s" % filepos
             if tag.tag == 'img':
                 recindex = None
                 for attr in self.IMAGE_ATTRS:
diff --git a/src/calibre/gui2/main.py b/src/calibre/gui2/main.py
index c2e755a742..0e59e35e1e 100644
--- a/src/calibre/gui2/main.py
+++ b/src/calibre/gui2/main.py
@@ -391,7 +391,7 @@ class Main(MainWindow, Ui_MainWindow):
     def change_output_format(self, x):
         of = unicode(x).strip()
         if of != prefs['output_format']:
-            if of not in ('LRF',):
+            if of not in ('LRF', 'EPUB'):
                 warning_dialog(self, 'Warning', 
                                '<p>%s support is still in beta. If you find bugs, please report them by opening a <a href="http://calibre.kovidgoyal.net">ticket</a>.'%of).exec_()
             prefs.set('output_format', of)