Hi Michael,
Thanks for getting back to me on a weekend.
I reported the issue to my hosting company who solved it quickly. For your information they said it was –
“your get request is tripping out some of the mod_security rules for remote file inclusion”.
When I asked for more details to report back here they sent me this –
“The ruleset is the same [across the two servers] however because you’re calling by different name, domain, and get-string values some sites may match and some not; we recommend that data be passed via POST for cleaner operation, generally.”
Thanks for your help again.
Simon
PS I can highly recommend my hosting company for their excellent support – http://www.5quidhosting.co.uk