Error: The connection was reset, but only in production mode

Hi, I wrote new website with administration for my client, but he insisted to run it on his hosting (Pipni, PHP 5.4.29).

When I run this application in “standard” production mode (auto detection), error “The connection was reset” is there. But, when I run it in Debug mode, everyting is OK (except displayed Tracy).

// not working - The connecton was reset
$configurator = new Nette\Configurator;

$configurator->enableDebugger(__DIR__ . '/log');

// working correctly
$configurator = new Nette\Configurator;

$configurator->setDebugMode(true);
$configurator->enableDebugger(__DIR__ . '/log');

// even with this line working correctly
Tracy\Debugger::$productionMode = TRUE;

I tried to run in debug mode and then set Tracy to production and that is working also, so problem is not in Tracy, but probably somewhere in production mode of Configurator / Application / something.

Does anybody have any idea, where that problem could be? Thanks a lot.