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;
        }
	
			




