Not pointing to hostopia server

[#1]

I have a hosted domain pointed to the CGI platform and have tried to change the DNS records to point to hostopia's servers but with no success. The files are uploading into the directory with no problem but when I try to access the uploaded files from another computer it's still the version that was transferred a few weeks ago - no edits are going live. I have used  91.136.8.9  as hostopia's servers - is this right? I changed the DNS records a week ago now.

[#2]

Yes that's the correct IP for the Hostopia servers.
If you run a

nslookup your-ccgi-website-domain-name

command in a command-prompt window on your PC does it return that IP address?

[#3]

Yes, it did, thanks. I've just realised I actually think it's the cached version on the work server that's getting me confused.