PDO & memcache Conflict?

Question

PHP

one)

$pdo = new PDO(...);
$mem_obj = new Memcache;
...
...
...
$this->mem_obj->connect('127.0.0.1', 11211);
$this->pdo->exec('UPDATE table SET id=1, unixtime = 1436392795');

2)

$pdo = new PDO(...);
$mem_obj = new Memcache
...
...
...
$this->pdo->exec('UPDATE table SET id=1, unixtime = 1436392795');
$this->mem_obj->connect('127.0.0.1', 11211);

After block execution 2) updates only id, unixtime 0 becomes
After block execution 1) all data is correctly updated... but arithmetic operations and the UNIX_TIMESTAMP() function in MySQL do not work
What is the reason for this? Is PDO also using port 11211?
id -> type INT VALUE 10
unixtime -> type BIGINT VALUE 20
MySQL database

Answer 1

the bug was found not at all where I expected, sorry for bothering you in vain, thanks everyone! There is no conflict!

Answer 2

$this is to blame? :)