sqlite repeats primary key autoincrement value after rollback

I expect that used and rollback(ed) PK values will be discarded by sqlite, but do not occur that way. here is the test:

PRAGMA foreign_keys = ON;
BEGIN TRANSACTION;
INSERT INTO _UIDlgt (id, TS) VALUES (null, '1421248181');
select max(id) from _UIDlgt;         -- shows  6  ok, there were previous records
ROLLBACK;
select max(id) from _UIDlgt;         -- shows  5  ok, was previous max value
INSERT INTO _UIDlgt (id, TS) VALUES (null, '1421248181');
select max(id) from _UIDlgt;         -- shows  6  I expect 7 !!!!

This is the table creation:

CREATE TABLE _UIDlgt (
   id              INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, 
   TS              INTEGER NOT NULL
);

Manual says that failed inserts skips PK values attempted to use, but noting about rollbacks.

The question is: Is there some setup to manage this behavior? or a trick?

Ms Sql Server works the way I expect. Sqlite version is 3.7.7.1 under PHP 5.4.11