A TimThumb error has occured

The following error(s) occured:

The remote file is not a valid image. Mimetype = 'text/html' File = /var/www/html/timthumb/cache/timthumbr90IQ6

Query String : src=http://www.eurcamping.it/img/bungalow/bungalow11.jpg&w=640&h=280&zc=1
TimThumb version : 2.8.13