Did you recently register the domain name and/or update DNS records? If recently registered, it would explain a delay in replication. Use NSLOOKUP to check the IP address that is resolving to the hdost name.
The DNS record was changed approximately 24 hours ago so I was expecting it to have a delay. I recently switched to 123-Reg's hosting so that I could make some modification to my server and then switched back.
I updated the DNS records from the control panel and I expected a wait of 24-48 hours for the TTLs to expire. About 3 hours ago everything was fine, it still hadn't swapped over to my server but then it started showing this login.
NSLookup shows that it is pointing to the correct IP although I have no idea where this control panel has come from, the changes I made to my server have nothing to do with it and I can access the server using the IP.
Not sure what you mean by the switching back and forth. So from your computer, nslookup resolves correctly? By any chance have you entered some static entries in a local Hosts file? When you use ping does the name to ip resolution equal to the response you get from nslookup?
Thanks for the help JorgeM, realised I was going completely and utterly mad...
The 'gsytourism.co.uk' record had refreshed and so it was displaying correctly but FireFox adds www. infront which hasn't updated yet so that is still pointing to the old IP, shall need to wait till the ISP record expires.