diff --git a/src/calibre/library/caches.py b/src/calibre/library/caches.py
index 01b7335bf4..5f4cfcba07 100644
--- a/src/calibre/library/caches.py
+++ b/src/calibre/library/caches.py
@@ -391,11 +391,11 @@ class ResultCache(SearchQueryParser): # {{{
     def build_numeric_relop_dict(self):
         self.numeric_search_relops = {
                         '=':[1, lambda r, q: r == q],
-                        '>':[1, lambda r, q: r > q],
-                        '<':[1, lambda r, q: r < q],
+                        '>':[1, lambda r, q: r is not None and r > q],
+                        '<':[1, lambda r, q: r is not None and r < q],
                         '!=':[2, lambda r, q: r != q],
-                        '>=':[2, lambda r, q: r >= q],
-                        '<=':[2, lambda r, q: r <= q]
+                        '>=':[2, lambda r, q: r is not None and r >= q],
+                        '<=':[2, lambda r, q: r is not None and r <= q]
                     }
 
     def get_numeric_matches(self, location, query, candidates, val_func = None):
@@ -406,17 +406,22 @@ class ResultCache(SearchQueryParser): # {{{
         if val_func is None:
             loc = self.field_metadata[location]['rec_index']
             val_func = lambda item, loc=loc: item[loc]
+        dt = self.field_metadata[location]['datatype']
+
+        q = ''
+        val_func = lambda item, loc=loc: item[loc]
+        cast = adjust = lambda x: x
 
         if query == 'false':
-            q = ''
-            relop = lambda x,y: x is None
-            val_func = lambda item, loc=loc: item[loc]
-            cast = adjust = lambda x: x
+            if dt == 'rating':
+                relop = lambda x,y: not bool(x)
+            else:
+                relop = lambda x,y: x is None
         elif query == 'true':
-            q = ''
-            relop = lambda x,y: x is not None
-            val_func = lambda item, loc=loc: item[loc]
-            cast = adjust = lambda x: x
+            if dt == 'rating':
+                relop = lambda x,y: bool(x)
+            else:
+                relop = lambda x,y: x is not None
         else:
             relop = None
             for k in self.numeric_search_relops.keys():
@@ -426,19 +431,15 @@ class ResultCache(SearchQueryParser): # {{{
             if relop is None:
                     (p, relop) = self.numeric_search_relops['=']
 
-            dt = self.field_metadata[location]['datatype']
             if dt == 'int':
-                cast = lambda x: int (x)  if x is not None else None
-                adjust = lambda x: x
-            elif  dt == 'rating':
                 cast = lambda x: int (x)
+            elif  dt == 'rating':
+                cast = lambda x: 0 if x is None else int (x)
                 adjust = lambda x: x/2
             elif dt in ('float', 'composite'):
-                cast = lambda x : float (x) if x is not None else None
-                adjust = lambda x: x
+                cast = lambda x : float (x)
             else: # count operation
                 cast = (lambda x: int (x))
-                adjust = lambda x: x
 
             if len(query) > 1:
                 mult = query[-1:].lower()
@@ -450,7 +451,8 @@ class ResultCache(SearchQueryParser): # {{{
             try:
                 q = cast(query) * mult
             except:
-                return matches
+                raise ParseException(query, len(query),
+                                     'Non-numeric value in query', self)
 
         for id_ in candidates:
             item = self._data[id_]
@@ -459,7 +461,7 @@ class ResultCache(SearchQueryParser): # {{{
             try:
                 v = cast(val_func(item))
             except:
-                v = 0
+                v = None
             if v:
                 v = adjust(v)
             if relop(v, q):
@@ -590,8 +592,7 @@ class ResultCache(SearchQueryParser): # {{{
             candidates = self.universal_set()
         if len(candidates) == 0:
             return matches
-        if location not in self.all_search_locations:
-            return matches
+        self.test_location_is_valid(location, query)
 
         if len(location) > 2 and location.startswith('@') and \
                     location[1:] in self.db_prefs['grouped_search_terms']:
diff --git a/src/calibre/library/database2.py b/src/calibre/library/database2.py
index 50b404b4be..7b4d52dbcd 100644
--- a/src/calibre/library/database2.py
+++ b/src/calibre/library/database2.py
@@ -854,6 +854,7 @@ class LibraryDatabase2(LibraryDatabase, SchemaUpgrade, CustomColumns):
         mi.uuid        = row[fm['uuid']]
         mi.title_sort  = row[fm['sort']]
         mi.last_modified = row[fm['last_modified']]
+        mi.size        = row[fm['size']]
         formats = row[fm['formats']]
         if not formats:
             formats = None
diff --git a/src/calibre/utils/search_query_parser.py b/src/calibre/utils/search_query_parser.py
index a50ca20fc1..387ad1487e 100644
--- a/src/calibre/utils/search_query_parser.py
+++ b/src/calibre/utils/search_query_parser.py
@@ -20,7 +20,7 @@ import sys, string, operator
 
 from calibre.utils.pyparsing import CaselessKeyword, Group, Forward, \
         CharsNotIn, Suppress, OneOrMore, MatchFirst, CaselessLiteral, \
-        Optional, NoMatch, ParseException, QuotedString
+        Optional, NoMatch, ParseException, QuotedString, Word
 from calibre.constants import preferred_encoding
 from calibre.utils.icu import sort_key
 
@@ -128,12 +128,8 @@ class SearchQueryParser(object):
         self._tests_failed = False
         self.optimize = optimize
         # Define a token
-        standard_locations = map(lambda x : CaselessLiteral(x)+Suppress(':'),
-                locations)
-        location = NoMatch()
-        for l in standard_locations:
-            location |= l
-        location     = Optional(location, default='all')
+        self.standard_locations = locations
+        location     = Optional(Word(string.ascii_letters+'#')+Suppress(':'), default='all')
         word_query   = CharsNotIn(string.whitespace + '()')
         #quoted_query = Suppress('"')+CharsNotIn('"')+Suppress('"')
         quoted_query = QuotedString('"', escChar='\\')
@@ -250,7 +246,14 @@ class SearchQueryParser(object):
                 raise ParseException(query, len(query), 'undefined saved search', self)
         return self._get_matches(location, query, candidates)
 
+    def test_location_is_valid(self, location, query):
+        if location not in self.standard_locations:
+            raise ParseException(query, len(query),
+                    _('No column exists with lookup name ') + location, self)
+
     def _get_matches(self, location, query, candidates):
+        location = location.lower()
+        self.test_location_is_valid(location, query)
         if self.optimize:
             return self.get_matches(location, query, candidates=candidates)
         else: