diff --git a/src/calibre/ebooks/fb2/fb2ml.py b/src/calibre/ebooks/fb2/fb2ml.py
index aaf8361b99..16c822d263 100644
--- a/src/calibre/ebooks/fb2/fb2ml.py
+++ b/src/calibre/ebooks/fb2/fb2ml.py
@@ -241,7 +241,7 @@ class FB2MLizer(object):
             if not fb2_text or fb2_text[-1] != ' ':
                 fb2_text.append(' ')
 
-        if hasattr(elem, 'text') and elem.text != None:
+        if hasattr(elem, 'text') and elem.text:
             if 'p' not in tag_stack:
                 fb2_text.append('<p>%s</p>' % prepare_string_for_xml(elem.text))
             else:
@@ -255,7 +255,7 @@ class FB2MLizer(object):
             close_tag_list.insert(0, tag_stack.pop())
         fb2_text += self.close_tags(close_tag_list)
 
-        if hasattr(elem, 'tail') and elem.tail != None:
+        if hasattr(elem, 'tail') and elem.tail:
             if 'p' not in tag_stack:
                 fb2_text.append('<p>%s</p>' % prepare_string_for_xml(elem.tail))
             else:
diff --git a/src/calibre/ebooks/pml/pmlml.py b/src/calibre/ebooks/pml/pmlml.py
index 862f0ea0ae..27e88eb48b 100644
--- a/src/calibre/ebooks/pml/pmlml.py
+++ b/src/calibre/ebooks/pml/pmlml.py
@@ -257,7 +257,7 @@ class PMLMLizer(object):
         # margin
 
         # Proccess tags that contain text.
-        if hasattr(elem, 'text') and elem.text != None and elem.text.strip() != '':
+        if hasattr(elem, 'text') and elem.text:
             text.append(self.remove_newlines(elem.text))
 
         for item in elem:
@@ -276,7 +276,7 @@ class PMLMLizer(object):
         #if style['page-break-after'] == 'always':
         #    text.append('\\p')
 
-        if hasattr(elem, 'tail') and elem.tail != None and elem.tail.strip() != '':
+        if hasattr(elem, 'tail') and elem.tail:
             text.append(self.remove_newlines(elem.tail))
 
         return text
diff --git a/src/calibre/ebooks/rb/rbml.py b/src/calibre/ebooks/rb/rbml.py
index 945e21c994..c293880343 100644
--- a/src/calibre/ebooks/rb/rbml.py
+++ b/src/calibre/ebooks/rb/rbml.py
@@ -191,7 +191,7 @@ class RBMLizer(object):
                 tag_stack.append(style_tag)
 
         # Proccess tags that contain text.
-        if hasattr(elem, 'text') and elem.text != None and elem.text.strip() != '':
+        if hasattr(elem, 'text') and elem.text:
             text.append(prepare_string_for_xml(elem.text))
 
         for item in elem:
@@ -203,7 +203,7 @@ class RBMLizer(object):
 
         text += self.close_tags(close_tag_list)
 
-        if hasattr(elem, 'tail') and elem.tail != None and elem.tail.strip() != '':
+        if hasattr(elem, 'tail') and elem.tail:
                 text.append(prepare_string_for_xml(elem.tail))
 
         return text
diff --git a/src/calibre/ebooks/txt/txtml.py b/src/calibre/ebooks/txt/txtml.py
index 59c3ea671a..45383675b4 100644
--- a/src/calibre/ebooks/txt/txtml.py
+++ b/src/calibre/ebooks/txt/txtml.py
@@ -94,7 +94,7 @@ class TXTMLizer(object):
         text = re.sub('(?<=.)%s(?=.)' % os.linesep, ' ', text)
 
         # Remove multiple spaces.
-        text = re.sub('[  ]+', ' ', text)
+        text = re.sub('[ ]{2,}', ' ', text)
 
         # Remove excessive newlines.
         text = re.sub('\n[ ]+\n', '\n\n', text)
@@ -172,15 +172,15 @@ class TXTMLizer(object):
         # Are we in a paragraph block?
         if tag in BLOCK_TAGS or style['display'] in BLOCK_STYLES:
             in_block = True
-            if not end.endswith(u'\n\n') and hasattr(elem, 'text') and elem.text != None and elem.text.strip() != '':
+            if not end.endswith(u'\n\n') and hasattr(elem, 'text') and elem.text:
                 text.append(u'\n\n')
 
         if tag in SPACE_TAGS:
-            if not end.endswith('u ') and hasattr(elem, 'text') and elem.text != None and elem.text.strip() != '':
+            if not end.endswith('u ') and hasattr(elem, 'text') and elem.text:
                 text.append(u' ')
 
         # Process tags that contain text.
-        if hasattr(elem, 'text') and elem.text != None and elem.text.strip() != '':
+        if hasattr(elem, 'text') and elem.text:
             text.append(elem.text)
 
         for item in elem:
@@ -192,7 +192,7 @@ class TXTMLizer(object):
         if in_block:
             text.append(u'\n\n')
 
-        if hasattr(elem, 'tail') and elem.tail != None and elem.tail.strip() != '':
+        if hasattr(elem, 'tail') and elem.tail:
             text.append(elem.tail)
 
         return text