diff --git a/Lib/sre.py b/Lib/sre.py
index 48d390a..6706fac 100644
--- a/Lib/sre.py
+++ b/Lib/sre.py
@@ -23,6 +23,8 @@
     "U", "IGNORECASE", "LOCALE", "MULTILINE", "DOTALL", "VERBOSE",
     "UNICODE", "error" ]
 
+__version__ = "2.1b2"
+
 # this module works under 1.5.2 and later.  don't use string methods
 import string
 
@@ -90,6 +92,7 @@
 def purge():
     "Clear the regular expression cache"
     _cache.clear()
+    _cache_repl.clear()
 
 def template(pattern, flags=0):
     "Compile a template pattern, returning a pattern object"
@@ -111,6 +114,8 @@
 # internals
 
 _cache = {}
+_cache_repl = {}
+
 _MAXCACHE = 100
 
 def _join(seq, sep):
@@ -134,6 +139,21 @@
     _cache[key] = p
     return p
 
+def _compile_repl(*key):
+    # internal: compile replacement pattern
+    p = _cache_repl.get(key)
+    if p is not None:
+        return p
+    repl, pattern = key
+    try:
+        p = sre_parse.parse_template(repl, pattern)
+    except error, v:
+        raise error, v # invalid expression
+    if len(_cache_repl) >= _MAXCACHE:
+        _cache_repl.clear()
+    _cache_repl[key] = p
+    return p
+
 def _expand(pattern, match, template):
     # internal: match.expand implementation hook
     template = sre_parse.parse_template(template, pattern)
@@ -148,7 +168,7 @@
     if callable(template):
         filter = template
     else:
-        template = sre_parse.parse_template(template, pattern)
+        template = _compile_repl(template, pattern)
         def filter(match, template=template):
             return sre_parse.expand_template(template, match)
     n = i = 0
diff --git a/Lib/sre_compile.py b/Lib/sre_compile.py
index ab2a2cc..44cb23e 100644
--- a/Lib/sre_compile.py
+++ b/Lib/sre_compile.py
@@ -105,9 +105,12 @@
         elif op is AT:
             emit(OPCODES[op])
             if flags & SRE_FLAG_MULTILINE:
-                emit(ATCODES[AT_MULTILINE.get(av, av)])
-            else:
-                emit(ATCODES[av])
+                av = AT_MULTILINE.get(av, av)
+            if flags & SRE_FLAG_LOCALE:
+                av = AT_LOCALE.get(av, av)
+            elif flags & SRE_FLAG_UNICODE:
+                av = AT_UNICODE.get(av, av)
+            emit(ATCODES[av])
         elif op is BRANCH:
             emit(OPCODES[op])
             tail = []
@@ -124,11 +127,10 @@
         elif op is CATEGORY:
             emit(OPCODES[op])
             if flags & SRE_FLAG_LOCALE:
-                emit(CHCODES[CH_LOCALE[av]])
+                av = CH_LOCALE[av]
             elif flags & SRE_FLAG_UNICODE:
-                emit(CHCODES[CH_UNICODE[av]])
-            else:
-                emit(CHCODES[av])
+                av = CH_UNICODE[av]
+            emit(CHCODES[av])
         elif op is GROUPREF:
             if flags & SRE_FLAG_IGNORECASE:
                 emit(OPCODES[OP_IGNORE[op]])
diff --git a/Lib/sre_constants.py b/Lib/sre_constants.py
index b429a33..bbe7880 100644
--- a/Lib/sre_constants.py
+++ b/Lib/sre_constants.py
@@ -11,7 +11,7 @@
 
 # update when constants are added or removed
 
-MAGIC = 20010115
+MAGIC = 20010320
 
 # max code word in this release
 
@@ -67,6 +67,10 @@
 AT_END = "at_end"
 AT_END_LINE = "at_end_line"
 AT_END_STRING = "at_end_string"
+AT_LOC_BOUNDARY = "at_loc_boundary"
+AT_LOC_NON_BOUNDARY = "at_loc_non_boundary"
+AT_UNI_BOUNDARY = "at_uni_boundary"
+AT_UNI_NON_BOUNDARY = "at_uni_non_boundary"
 
 # categories
 CATEGORY_DIGIT = "category_digit"
@@ -119,7 +123,9 @@
 
 ATCODES = [
     AT_BEGINNING, AT_BEGINNING_LINE, AT_BEGINNING_STRING, AT_BOUNDARY,
-    AT_NON_BOUNDARY, AT_END, AT_END_LINE, AT_END_STRING
+    AT_NON_BOUNDARY, AT_END, AT_END_LINE, AT_END_STRING,
+    AT_LOC_BOUNDARY, AT_LOC_NON_BOUNDARY, AT_UNI_BOUNDARY,
+    AT_UNI_NON_BOUNDARY
 ]
 
 CHCODES = [
@@ -157,6 +163,16 @@
     AT_END: AT_END_LINE
 }
 
+AT_LOCALE = {
+    AT_BOUNDARY: AT_LOC_BOUNDARY,
+    AT_NON_BOUNDARY: AT_LOC_NON_BOUNDARY
+}
+
+AT_UNICODE = {
+    AT_BOUNDARY: AT_UNI_BOUNDARY,
+    AT_NON_BOUNDARY: AT_UNI_NON_BOUNDARY
+}
+
 CH_LOCALE = {
     CATEGORY_DIGIT: CATEGORY_DIGIT,
     CATEGORY_NOT_DIGIT: CATEGORY_NOT_DIGIT,
diff --git a/Lib/sre_parse.py b/Lib/sre_parse.py
index 3840365..44626bd 100644
--- a/Lib/sre_parse.py
+++ b/Lib/sre_parse.py
@@ -638,6 +638,16 @@
     s = Tokenizer(source)
     p = []
     a = p.append
+    def literal(literal, p=p):
+        if p and p[-1][0] is LITERAL:
+            p[-1] = LITERAL, p[-1][1] + literal
+        else:
+            p.append((LITERAL, literal))
+    sep = source[:0]
+    if type(sep) is type(""):
+        char = chr
+    else:
+        char = unichr
     while 1:
         this = s.get()
         if this is None:
@@ -681,33 +691,42 @@
                         break
                 if not code:
                     this = this[1:]
-                    code = LITERAL, atoi(this[-6:], 8) & 0xff
-                a(code)
+                    code = LITERAL, char(atoi(this[-6:], 8) & 0xff)
+                if code[0] is LITERAL:
+                    literal(code[1])
+                else:
+                    a(code)
             else:
                 try:
-                    a(ESCAPES[this])
+                    this = char(ESCAPES[this][1])
                 except KeyError:
-                    for c in this:
-                        a((LITERAL, ord(c)))
+                    pass
+                literal(this)
         else:
-            a((LITERAL, ord(this)))
-    return p
+            literal(this)
+    # convert template to groups and literals lists
+    i = 0
+    groups = []
+    literals = []
+    for c, s in p:
+        if c is MARK:
+            groups.append((i, s))
+            literals.append(None)
+        else:
+            literals.append(s)
+        i = i + 1
+    return groups, literals
 
 def expand_template(template, match):
-    # XXX: <fl> this is sooooo slow.  drop in the slicelist code instead
-    p = []
-    a = p.append
+    g = match.group
     sep = match.string[:0]
-    if type(sep) is type(""):
-        char = chr
-    else:
-        char = unichr
-    for c, s in template:
-        if c is LITERAL:
-            a(char(s))
-        elif c is MARK:
-            s = match.group(s)
+    groups, literals = template
+    literals = literals[:]
+    try:
+        for index, group in groups:
+            literals[index] = s = g(group)
             if s is None:
-                raise error, "empty group"
-            a(s)
-    return string.join(p, sep)
+                raise IndexError
+    except IndexError:
+        raise error, "empty group"
+    return string.join(literals, sep)
diff --git a/Lib/test/re_tests.py b/Lib/test/re_tests.py
index aacd916..7c5dc89 100755
--- a/Lib/test/re_tests.py
+++ b/Lib/test/re_tests.py
@@ -639,3 +639,14 @@
     # bug 130748: ^* should be an error (nothing to repeat)
     (r'^*', '', SYNTAX_ERROR),
 ]
+
+try:
+    u = eval("u'\N{LATIN CAPITAL LETTER A WITH DIAERESIS}'")
+except SyntaxError:
+    pass
+else:
+    tests.extend([
+    # bug 410271: \b broken under locales
+    (r'\b.\b', 'a', SUCCEED, 'found', 'a'),
+    (r'(?u)\b.\b', u, SUCCEED, 'found', u),
+    ])
diff --git a/Lib/test/test_sre.py b/Lib/test/test_sre.py
index 88c0d62..031cda6 100644
--- a/Lib/test/test_sre.py
+++ b/Lib/test/test_sre.py
@@ -329,6 +329,8 @@
                 u = unicode(s, "latin-1")
             except NameError:
                 pass
+            except TypeError:
+                continue # skip unicode test strings
             else:
                 result=obj.search(u)
                 if result==None: