I would check Imagick integration.
Checked and works without problems since almost a year now.
If you are sure there is no bug in the code, I'll forward it to our server technicians. For me the code looks pretty okay... Strange.
PHP:
if (XenForo_Application::get('options')->imageLibrary['class'] == 'imPecl')
{
$class = new Imagick();
foreach ($imageArray as $index => $image)
{
$class->readimage($image);
$class->rotateimage(new ImagickPixel(), $angle);
$class->setimageformat($photo['extension']);
$class->writeImages($newImageArray[$index], true);
}
$class->destroy();
return true;
}