diff --git a/src/calibre/gui2/convert/heuristics.py b/src/calibre/gui2/convert/heuristics.py
index 525d5ba2f1..4735782f52 100644
--- a/src/calibre/gui2/convert/heuristics.py
+++ b/src/calibre/gui2/convert/heuristics.py
@@ -34,8 +34,11 @@ class HeuristicsWidget(Widget, Ui_Form):
     def break_cycles(self):
         Widget.break_cycles(self)
         
-        self.opt_enable_heuristics.stateChanged.disconnect()
-        self.opt_unwrap_lines.stateChanged.disconnect()
+        try:
+            self.opt_enable_heuristics.stateChanged.disconnect()
+            self.opt_unwrap_lines.stateChanged.disconnect()
+        except:
+            pass
         
     def set_value_handler(self, g, val):
         if val is None and g is self.opt_html_unwrap_factor:
diff --git a/src/calibre/gui2/convert/search_and_replace.py b/src/calibre/gui2/convert/search_and_replace.py
index fff75a29ba..af944a74d1 100644
--- a/src/calibre/gui2/convert/search_and_replace.py
+++ b/src/calibre/gui2/convert/search_and_replace.py
@@ -36,7 +36,7 @@ class SearchAndReplaceWidget(Widget, Ui_Form):
         self.opt_sr3_search.break_cycles()
 
     def pre_commit_check(self):
-        for x in ('sr1-search', 'sr2-search', 'sr3-search'):
+        for x in ('sr1_search', 'sr2_search', 'sr3_search'):
             x = getattr(self, 'opt_'+x)
             try:
                 pat = unicode(x.regex)
@@ -45,5 +45,4 @@ class SearchAndReplaceWidget(Widget, Ui_Form):
                 error_dialog(self, _('Invalid regular expression'),
                              _('Invalid regular expression: %s')%err).exec_()
                 return False
-            
-
+        return True