diff --git a/src/calibre/ebooks/lit/reader.py b/src/calibre/ebooks/lit/reader.py
index 06f5ebdabb..407aedae1f 100644
--- a/src/calibre/ebooks/lit/reader.py
+++ b/src/calibre/ebooks/lit/reader.py
@@ -276,8 +276,11 @@ class UnBinary(object):
                     state = 'get attr'
                 elif count > 0:
                     if not in_censorship:
-                        self.buf.write(c.encode(
-                            'ascii', 'xmlcharrefreplace'))
+                        if c == '"':
+                            c = '"'
+                        elif c == '<':
+                            c = '&lt;'
+                        self.buf.write(c.encode('ascii', 'xmlcharrefreplace'))
                     count -= 1
                 if count == 0:
                     if not in_censorship:
diff --git a/src/calibre/ebooks/oeb/transforms/flatcss.py b/src/calibre/ebooks/oeb/transforms/flatcss.py
index ee7d7fa0b2..63466ac551 100644
--- a/src/calibre/ebooks/oeb/transforms/flatcss.py
+++ b/src/calibre/ebooks/oeb/transforms/flatcss.py
@@ -37,6 +37,8 @@ class KeyMapper(object):
 
     @staticmethod
     def relate(size, base):
+        if size == 0:
+            return base
         size = float(size)
         base = float(base)
         if abs(size - base) < 0.1: return 0
@@ -48,6 +50,7 @@ class KeyMapper(object):
         return result
         
     def __getitem__(self, ssize):
+        ssize = asfloat(ssize, 0)
         if ssize in self.cache:
             return self.cache[ssize]
         dsize = self.map(ssize)
@@ -66,6 +69,7 @@ class ScaleMapper(object):
         self.dscale = float(dbase) / float(sbase)
 
     def __getitem__(self, ssize):
+        ssize = asfloat(ssize, 0)
         dsize = ssize * self.dscale
         return dsize