diff --git a/src/calibre/ebooks/conversion/utils.py b/src/calibre/ebooks/conversion/utils.py
index 27dacdf5fb..52d1bcc619 100644
--- a/src/calibre/ebooks/conversion/utils.py
+++ b/src/calibre/ebooks/conversion/utils.py
@@ -190,7 +190,7 @@ class PreProcessor(object):
         line_ending = "\s*</(span|p|div)>\s*(</(p|span|div)>)?"
         blanklines = "\s*(?P<up2threeblanks><(p|span|div)[^>]*>\s*(<(p|span|div)[^>]*>\s*</(span|p|div)>\s*)</(span|p|div)>\s*){0,3}\s*"
         line_opening = "<(span|div|p)[^>]*>\s*(<(span|div|p)[^>]*>)?\s*"
-        txt_line_wrap = u"(\u0020|\u0009)*\n"
+        txt_line_wrap = u"((\u0020|\u0009)*\n){1,4}"
         
         unwrap_regex = lookahead+line_ending+blanklines+line_opening
         if format == 'txt':
@@ -357,6 +357,6 @@ class PreProcessor(object):
         html = blankreg.sub('\n'+r'\g<openline>'+u'\u00a0'+r'\g<closeline>', html)
 
         # Center separator lines
-        html = re.sub(u'<p>\s*(?P<break>([*#•]+\s*)+)\s*</p>', '<p style="text-align:center">' + '\g<break>' + '</p>', html)
+        html = re.sub(u'<(?P<outer>p|div)[^>]*>\s*(<(?P<inner1>font|span|[ibu])[^>]*>)?\s*(<(?P<inner2>font|span|[ibu])[^>]*>)?\s*(<(?P<inner3>font|span|[ibu])[^>]*>)?\s*(?P<break>([*#•]+\s*)+)\s*(</(?P=inner3)>)?\s*(</(?P=inner2)>)?\s*(</(?P=inner1)>)?\s*</(?P=outer)>', '<p style="text-align:center">' + '\g<break>' + '</p>', html)
 
         return html
diff --git a/src/calibre/ebooks/txt/input.py b/src/calibre/ebooks/txt/input.py
index 98756c5fa1..eac46385a7 100644
--- a/src/calibre/ebooks/txt/input.py
+++ b/src/calibre/ebooks/txt/input.py
@@ -90,7 +90,7 @@ class TXTInput(InputFormatPlugin):
             
             # We don't check for block because the processor assumes block.
             # single and print at transformed to block for processing.
-            if options.paragraph_type == 'single' or 'unformatted':
+            if options.paragraph_type in ('single', 'unformatted'):
                 txt = separate_paragraphs_single_line(txt)
             elif options.paragraph_type == 'print':
                 txt = separate_paragraphs_print_formatted(txt)