We have been having people downloading the entire site and hogging up our bandwidth so I have put in a blocker which stops people from connecting multiple times. The block is working very well and for the most part only blocking people who should be being blocked.

Because most browser now-a-days create multiple connections to per page load this can cause legitimate traffic to sometimes get blocked. If this happens you will see "Service Temporally Unavailable" which will last for a minute.