Thanks for getting back to me.
I think i have a problem with the wp-con file.
My host is HEART INTERNET who says this
Checking the plugin you are using, this notes that curl support is required. Curl is available on the shared hosting however a script within the hosting cannot call files locally stored via curl.
This is due to http loopbacks (a script calling a local file via the domain url) being disabled within the shared environment.
This is done to prevent the possibility that mis-configured scripts could enter, essentially, an "infinite loop", making call-backs to themselves. Such a situation is extremely detrimental to server performance, and would negatively impact other users also on this shared server.
Unfortunately we are not able to lift this block on a per-site or per-script basis, so you will need to see if you are able to reconfigure the script (or contact the script authors for assistance doing this, some wordpress backups do have an alternate method), or use an alternative script that doesn't require HTTP requests to its own server.
Any ideas who we can get round this?