diff --git a/src/calibre/ebooks/oeb/iterator.py b/src/calibre/ebooks/oeb/iterator.py
index 2312ea308b..ed0ca6c3f4 100644
--- a/src/calibre/ebooks/oeb/iterator.py
+++ b/src/calibre/ebooks/oeb/iterator.py
@@ -184,6 +184,8 @@ class EbookIterator(object):
 
         if processed or plumber.input_fmt.lower() in ('pdb', 'pdf', 'rb') and \
                 not hasattr(self.pathtoopf, 'manifest'):
+            if hasattr(self.pathtoopf, 'manifest'):
+                self.pathtoopf = write_oebbook(self.pathtoopf, self.base)
             self.pathtoopf = create_oebbook(self.log, self.pathtoopf, plumber.opts,
                     plumber.input_plugin)
         if hasattr(self.pathtoopf, 'manifest'):
diff --git a/src/calibre/gui2/__init__.py b/src/calibre/gui2/__init__.py
index f467d5cc80..5aad257711 100644
--- a/src/calibre/gui2/__init__.py
+++ b/src/calibre/gui2/__init__.py
@@ -461,7 +461,7 @@ class FileDialog(QObject):
 
     def get_files(self):
         if self.selected_files is None:
-            return tuple(os.path.abspath(qstring_to_unicode(i)) for i in self.fd.selectedFiles())
+            return tuple(os.path.abspath(unicode(i)) for i in self.fd.selectedFiles())
         return tuple(self.selected_files)
 
 
diff --git a/src/calibre/gui2/convert/regex_builder.py b/src/calibre/gui2/convert/regex_builder.py
index 3f31a635a6..8d00de2fe8 100644
--- a/src/calibre/gui2/convert/regex_builder.py
+++ b/src/calibre/gui2/convert/regex_builder.py
@@ -7,12 +7,12 @@ __docformat__ = 'restructuredtext en'
 import re
 
 from PyQt4.QtCore import SIGNAL, Qt
-from PyQt4.QtGui import QDialog, QWidget, QDialogButtonBox, QFileDialog, \
+from PyQt4.QtGui import QDialog, QWidget, QDialogButtonBox, \
                         QBrush, QTextCursor, QTextEdit
 
 from calibre.gui2.convert.regex_builder_ui import Ui_RegexBuilder
 from calibre.gui2.convert.xexp_edit_ui import Ui_Form as Ui_Edit
-from calibre.gui2 import error_dialog
+from calibre.gui2 import error_dialog, choose_files
 from calibre.ebooks.oeb.iterator import EbookIterator
 from calibre.gui2.dialogs.choose_format import ChooseFormatDialog
 
@@ -94,9 +94,10 @@ class RegexBuilder(QDialog, Ui_RegexBuilder):
 
     def button_clicked(self, button):
         if button == self.button_box.button(QDialogButtonBox.Open):
-            name = QFileDialog.getOpenFileName(self, _('Open book'), _('~'))
-            if name:
-                self.open_book(unicode(name))
+            files = choose_files(self, 'regexp tester dialog', _('Open book'),
+                    select_only_single_file=True)
+            if files:
+                self.open_book(files[0])
         if button == self.button_box.button(QDialogButtonBox.Ok):
             self.accept()