diff --git a/src/calibre/gui2/comments_editor.py b/src/calibre/gui2/comments_editor.py
index c043fccba4..ac8ab13d20 100644
--- a/src/calibre/gui2/comments_editor.py
+++ b/src/calibre/gui2/comments_editor.py
@@ -18,11 +18,11 @@ from PyQt4.QtWebKit import QWebView, QWebPage
 
 from calibre.ebooks.chardet import xml_to_unicode
 from calibre import xml_replace_entities, prepare_string_for_xml
-from calibre.gui2 import open_url
+from calibre.gui2 import open_url, error_dialog
 from calibre.utils.soupparser import fromstring
 from calibre.utils.config import tweaks
 
-class PageAction(QAction): # {{{
+class PageAction(QAction):  # {{{
 
     def __init__(self, wac, icon, text, checkable, view):
         QAction.__init__(self, QIcon(I(icon+'.png')), text, view)
@@ -43,14 +43,15 @@ class PageAction(QAction): # {{{
         self.page_action.trigger()
 
     def update_state(self, *args):
-        if sip.isdeleted(self) or sip.isdeleted(self.page_action): return
+        if sip.isdeleted(self) or sip.isdeleted(self.page_action):
+            return
         if self.isCheckable():
             self.setChecked(self.page_action.isChecked())
         self.setEnabled(self.page_action.isEnabled())
 
 # }}}
 
-class BlockStyleAction(QAction): # {{{
+class BlockStyleAction(QAction):  # {{{
 
     def __init__(self, text, name, view):
         QAction.__init__(self, text, view)
@@ -62,7 +63,7 @@ class BlockStyleAction(QAction): # {{{
 
 # }}}
 
-class EditorWidget(QWebView): # {{{
+class EditorWidget(QWebView):  # {{{
 
     def __init__(self, parent=None):
         QWebView.__init__(self, parent)
@@ -157,6 +158,8 @@ class EditorWidget(QWebView): # {{{
         self.action_insert_link = QAction(QIcon(I('insert-link.png')),
                 _('Insert link'), self)
         self.action_insert_link.triggered.connect(self.insert_link)
+        self.pageAction(QWebPage.ToggleBold).changed.connect(self.update_link_action)
+        self.action_insert_link.setEnabled(False)
         self.action_clear = QAction(QIcon(I('edit-clear')), _('Clear'), self)
         self.action_clear.triggered.connect(self.clear_text)
 
@@ -166,6 +169,10 @@ class EditorWidget(QWebView): # {{{
         self.setHtml('')
         self.set_readonly(False)
 
+    def update_link_action(self):
+        wac = self.pageAction(QWebPage.ToggleBold)
+        self.action_insert_link.setEnabled(wac.isEnabled())
+
     def set_readonly(self, what):
         self.readonly = what
         self.page().setContentEditable(not self.readonly)
@@ -202,12 +209,16 @@ class EditorWidget(QWebView): # {{{
         url = self.parse_link(unicode(link))
         if url.isValid():
             url = unicode(url.toString())
+            self.setFocus(Qt.OtherFocusReason)
             if name:
                 self.exec_command('insertHTML',
                         '<a href="%s">%s</a>'%(prepare_string_for_xml(url, True),
                             prepare_string_for_xml(name)))
             else:
                 self.exec_command('createLink', url)
+        else:
+            error_dialog(self, _('Invalid URL'),
+                         _('The url %r is invalid') % unicode(link), show=True)
 
     def ask_link(self):
         d = QDialog(self)
@@ -362,9 +373,9 @@ class Highlighter(QSyntaxHighlighter):
         self.colors['doctype']        = QColor(192, 192, 192)
         self.colors['entity']         = QColor(128, 128, 128)
         self.colors['tag']            = QColor(136,  18, 128)
-        self.colors['comment']        = QColor( 35, 110,  37)
+        self.colors['comment']        = QColor(35, 110,  37)
         self.colors['attrname']       = QColor(153,  69,   0)
-        self.colors['attrval']        = QColor( 36,  36, 170)
+        self.colors['attrval']        = QColor(36,  36, 170)
 
     def highlightBlock(self, text):
         state = self.previousBlockState()
@@ -378,8 +389,8 @@ class Highlighter(QSyntaxHighlighter):
                 start = pos
                 while pos < len_:
                     if text.mid(pos, 3) == "-->":
-                        pos += 3;
-                        state = State_Text;
+                        pos += 3
+                        state = State_Text
                         break
                     else:
                         pos += 1
@@ -422,7 +433,7 @@ class Highlighter(QSyntaxHighlighter):
                     if ch == QChar('>'):
                         state = State_Text
                         break
-                self.setFormat(start, pos - start, self.colors['tag']);
+                self.setFormat(start, pos - start, self.colors['tag'])
 
             # anywhere after tag name and before tag closing ('>')
             elif state == State_InsideTag:
@@ -489,7 +500,7 @@ class Highlighter(QSyntaxHighlighter):
                     # just stop at non-space or tag delimiter
                     start = pos
                     while pos < len_:
-                        ch = text.at(pos);
+                        ch = text.at(pos)
                         if ch.isSpace():
                             break
                         if ch in (QChar('>'), QChar('/')):
@@ -538,7 +549,7 @@ class Highlighter(QSyntaxHighlighter):
                                 state = State_DocType
                             else:
                                 state = State_TagStart
-                        break;
+                        break
                     elif ch == QChar('&'):
                         start = pos
                         while pos < len_ and text.at(pos) != QChar(';'):
@@ -549,12 +560,11 @@ class Highlighter(QSyntaxHighlighter):
                     else:
                         pos += 1
 
-
         self.setCurrentBlockState(state)
 
 # }}}
 
-class Editor(QWidget): # {{{
+class Editor(QWidget):  # {{{
 
     def __init__(self, parent=None, one_line_toolbar=False):
         QWidget.__init__(self, parent)
@@ -650,13 +660,13 @@ class Editor(QWidget): # {{{
         return property(fget=fget, fset=fset)
 
     def change_tab(self, index):
-        #print 'reloading:', (index and self.wyswyg_dirty) or (not index and
+        # print 'reloading:', (index and self.wyswyg_dirty) or (not index and
         #        self.source_dirty)
-        if index == 1: # changing to code view
+        if index == 1:  # changing to code view
             if self.wyswyg_dirty:
                 self.code_edit.setPlainText(self.editor.html)
                 self.wyswyg_dirty = False
-        elif index == 0: #changing to wyswyg
+        elif index == 0:  # changing to wyswyg
             if self.source_dirty:
                 self.editor.html = unicode(self.code_edit.toPlainText())
                 self.source_dirty = False
@@ -687,4 +697,5 @@ if __name__ == '__main__':
     w.show()
     w.html = '<b>testing</b>'
     app.exec_()
-    #print w.html
+    # print w.html
+