File upload not working both in sanbox and on other host.
on my host both checks cause errors
(with txt, and doc on default list of extensions and mimes):
//CHECK EXTENSION        
        if (!$this->checkExtension($file->extension))
		{
			$app->enqueueMessage(JText::sprintf( "XXXXXX_UPLOAD_THIS_FILE_EXTENSION_IS_NOT_ACCEPTED_THE_ACCEPTED_FILES_ARE",
								$file->extension,
								$this->getAllowedExtensions()
								), 'notice');
			return false;
		}
and
		//CHECK MIME HEADER
		$this->file->mime = $this->getMime($this->file->tmp);
		if (!$this->checkMime($this->file->mime))
        {
			$app->enqueueMessage(JText::sprintf( "XXXXXX_UPLOAD_MIME_TYPE_NOT_VALID_ALLOWED_MIMES_ARE",
								$this->file->mime,
								$this->getAllowedMimes()), 'error');
			return false;
		}