diff --git a/src/calibre/ebooks/__init__.py b/src/calibre/ebooks/__init__.py
index 0fceb4bcf8..73bd375812 100644
--- a/src/calibre/ebooks/__init__.py
+++ b/src/calibre/ebooks/__init__.py
@@ -7,7 +7,10 @@ from various formats.
 '''
 
 class ConversionError(Exception):
-    pass
+    
+    def __init__(self, msg, only_msg=False):
+        Exception.__init__(self, msg)
+        self.only_msg = only_msg
 
 class UnknownFormatError(Exception):
     pass
diff --git a/src/calibre/ebooks/lrf/pdf/convert_from.py b/src/calibre/ebooks/lrf/pdf/convert_from.py
index 9c201da224..2adb9a12a7 100644
--- a/src/calibre/ebooks/lrf/pdf/convert_from.py
+++ b/src/calibre/ebooks/lrf/pdf/convert_from.py
@@ -38,7 +38,7 @@ def generate_html(pathtopdf, logger):
             p = popen(cmd, stderr=subprocess.PIPE, stdout=subprocess.PIPE)
         except OSError, err:
             if err.errno == 2:
-                raise ConversionError(_('Could not find pdftohtml, check it is in your PATH'))
+                raise ConversionError(_('Could not find pdftohtml, check it is in your PATH'), True)
             else:
                 raise
         logger.info(p.stdout.read())
@@ -47,10 +47,10 @@ def generate_html(pathtopdf, logger):
             err = p.stderr.read()
             raise ConversionError, err
         if not os.path.exists(index) or os.stat(index).st_size < 100:
-            raise ConversionError(os.path.basename(pathtopdf) + _(' does not allow copying of text.'))
+            raise ConversionError(os.path.basename(pathtopdf) + _(' does not allow copying of text.'), True)
         raw = open(index).read(4000)
         if not '<br' in raw:
-            raise ConversionError(os.path.basename(pathtopdf) + _(' is an image based PDF. Only conversion of text based PDFs is supported.'))
+            raise ConversionError(os.path.basename(pathtopdf) + _(' is an image based PDF. Only conversion of text based PDFs is supported.'), True)
     finally:
         os.chdir(cwd)
     return index
diff --git a/src/calibre/gui2/main.py b/src/calibre/gui2/main.py
index 98e44485d2..02d66e3b7c 100644
--- a/src/calibre/gui2/main.py
+++ b/src/calibre/gui2/main.py
@@ -1076,6 +1076,9 @@ class Main(MainWindow, Ui_MainWindow):
             print >>sys.stderr, formatted_traceback.encode('utf8', 'ignore') if isinstance(formatted_traceback, unicode) else formatted_traceback
         except:
             pass
+        if getattr(exception, 'only_msg', False):
+            error_dialog(self, _('Conversion Error'), unicode(exception)).exec_()
+            return
         msg =  u'<p><b>%s</b>: %s</p>'%exception
         msg += u'<p>Failed to perform <b>job</b>: '+description
         msg += u'<p>Detailed <b>traceback</b>:<pre>'