Thanks for the info, I have just been working with our dev guys and we now have got to the route of the issue.
it’s actually a little more complex than initially thought but it is due to permission settings.
Were running on a windows server so use IIS7 to run PHP
as standard php uses the default root “tmp” folder permissions for upload files the default on windows had limited permissions which needs to remain as is (as we require quite strick access protocal on other parts of the site).
So the dev guys had to update the ini.php (serverside php file) settings to pull the permissions form a different folder (which they set up with the correct permissions) this should now resolve the permission issue on all uploaded files.
we need to restart IIS on the server but can’t do this till later on today.
So essentially the issue is with using windows IIS7 + the server Set-up, and PHP.
Will update to confirm if this was successful.