diff --git a/src/calibre/gui2/library.py b/src/calibre/gui2/library.py
index b21f27bad9..520a08e36a 100644
--- a/src/calibre/gui2/library.py
+++ b/src/calibre/gui2/library.py
@@ -326,7 +326,10 @@ class BooksModel(QAbstractTableModel):
         ans = []
         for row in (row.row() for row in rows):
             format = None
-            db_formats = set(self.db.formats(row).lower().split(','))
+            fmts = self.db.formats(row)
+            if not fmts:
+                return []
+            db_formats = set(fmts.lower().split(','))
             available_formats = set([f.lower() for f in formats]) 
             u = available_formats.intersection(db_formats)
             for f in formats:
diff --git a/src/calibre/library/database2.py b/src/calibre/library/database2.py
index d224555b63..a5b0c83a41 100644
--- a/src/calibre/library/database2.py
+++ b/src/calibre/library/database2.py
@@ -577,7 +577,7 @@ class LibraryDatabase2(LibraryDatabase):
         return set([f[0] for f in formats])
     
     def formats(self, index, index_is_id=False):
-        ''' Return available formats as a comma separated list or None if htere are no available formats '''
+        ''' Return available formats as a comma separated list or None if there are no available formats '''
         id = index if index_is_id else self.id(index)
         path = os.path.join(self.library_path, self.path(id, index_is_id=True))
         try: