diff --git a/anki/db.py b/anki/db.py
index f75499c65..530d30e21 100644
--- a/anki/db.py
+++ b/anki/db.py
@@ -15,7 +15,7 @@ from anki.hooks import runHook
 
 class DB(object):
     def __init__(self, path, text=None):
-        self._db = sqlite.connect(path, timeout=0, isolation_level=None)
+        self._db = sqlite.connect(path, timeout=0)
         if text:
             self._db.text_factory = text
         self._path = path
@@ -23,7 +23,7 @@ class DB(object):
 
     def execute(self, sql, *a, **ka):
         if self.echo:
-            print sql, a, ka
+            print sql #, a, ka
         if ka:
             # execute("...where id = :id", id=5)
             res = self._db.execute(sql, ka)
@@ -34,7 +34,7 @@ class DB(object):
 
     def executemany(self, sql, l):
         if self.echo:
-            print sql, l
+            print sql #, l
         self._db.executemany(sql, l)
 
     def commit(self):
diff --git a/anki/deck.py b/anki/deck.py
index d5bd8ecd6..8c691988a 100644
--- a/anki/deck.py
+++ b/anki/deck.py
@@ -119,10 +119,6 @@ qconf=?, conf=?, data=?""",
         self.lock()
 
     def lock(self):
-        # we don't know if pysqlite has taken out a transaction from under us,
-        # so make sure we're committed
-        self.db.commit()
-        self.db.execute("begin exclusive")
         self.db.execute("update deck set mod=mod")
 
     def close(self, save=True):
@@ -737,6 +733,7 @@ insert into undoLog values (null, 'insert into %(t)s (rowid""" % {'t': table}
                 sql += ",' || quote(old.%s) ||'" % c
             sql += ")'); end"
             self.db.execute(sql)
+        self.lock()
 
     def undoName(self):
         for n in reversed(self.undoStack):
@@ -848,7 +845,6 @@ seq > :s and seq <= :e order by seq desc""", s=start, e=end)
         return "\n".join(problems)
 
     def optimize(self):
-        self.db.commit()
         self.db.execute("vacuum")
         self.db.execute("analyze")
         self.lock()
diff --git a/anki/storage.py b/anki/storage.py
index 8a092cc8e..19358ee19 100644
--- a/anki/storage.py
+++ b/anki/storage.py
@@ -242,8 +242,7 @@ def _upgradeSchema(db):
     # move into temp table
     _moveTable(db, "cards", True)
     # use the new order to rewrite card ids
-    map = dict(db.all("select id, rowid from cards2"))
-    _insertWithIdChange(db, map, 0, "reviewHistory", 12)
+    cardmap = dict(db.all("select id, rowid from cards2"))
     # move back, preserving new ids
     db.execute("""
 insert into cards select rowid, factId, cardModelId, 1, cast(created as int),
@@ -321,15 +320,27 @@ name, "{}", "{}", ?, "" from models2""", simplejson.dumps(
 
     # reviewHistory -> revlog
     ###########
-    db.execute("""
-insert or ignore into revlog select
+    # fetch the data so we can rewrite ids quickly
+    r = []
+    for row in db.execute("""
+select
 cast(time*1000 as int), cardId, ease, reps,
 cast(lastInterval as int), cast(nextInterval as int),
 cast(nextFactor*1000 as int), cast(min(thinkingTime, 60)*1000 as int),
-0 from reviewHistory""")
+0 from reviewHistory"""):
+        row = list(row)
+        # new card ids
+        try:
+            row[1] = cardmap[row[1]]
+        except:
+            # id doesn't exist
+            continue
+        # no ease 0 anymore
+        row[2] = row[2] or 1
+        r.append(row)
+    db.executemany(
+        "insert or ignore into revlog values (?,?,?,?,?,?,?,?,?)", r)
     db.execute("drop table reviewHistory")
-    # convert old ease0 into ease1
-    db.execute("update revlog set ease = 1 where ease = 0")
 
     # longer migrations
     ###########