SnippetArea forcing components to render twice

Recently I have encountered a weird behaviour when using snippet-area macro in Nette 2.3 where I have some static control.

First I have component Foo:

class Foo extends \Nette\Application\UI\Control
{
    private static $count = 1;

    public function render()
    {
        $this->template->setFile(__DIR__ . '/foo.latte');
        $this->template->count = self::$count++;
        $this->template->render();
    }

    public function handleShow()
    {
        $this->redrawControl();
    }
}

{snippet}
    {$count}
{/snippet}

And I have template Homepage/default.latte

{* abridged *}
{snippetArea flashes-wrapper}
	{include ../flashes.latte}
{/snippetArea}
{control modal}
<a href="/?do=modal-show" class="ajax">open modal</a>
{* abridged *}

Where flashes.latte contains:

{snippet flashes}
    <div n:foreach="$flashes as $flash" n:class="flash, $flash->type">{$flash->message}</div>
{/snippet}

And BasePresenter.php

protected function beforeRender()
    {
        parent::beforeRender();
        $this->flashMessage(
            "You can not publish demands nor offers until you verify your email. We have sent email with verification link after your registration, please check your email box (sometimes it can end up in SPAM)"
        );
        if ($this->isAjax()) {
            $this->redrawControl('flashes-wrapper');
            $this->redrawControl('flashes');
        }
    }

---

Expected behaviour:

1. Click on the ajax link
2. Flash message should be added
3. Component should be rerendered and show “1”

Actual result: the number is “2” when loaded via ajax, or “1” when loaded into new tab (without ajax).

Is this inconsistency known? Is it a bug?

UPDATE: when I inline the flashes.latte the problem disappears.