Hi Suz702,
This is a webshield alert, and as long as you have clicked on the 'abort connection' button, you should be safe.
This kid of alert is very common with many legitimate sites becoming infected.
The reason many other people are able to get to the site could be from using another av, and many others don't even scan for this kind of thing, let alone alert on it.
Please could you provide us with the site url?
Please could you make the link unclickable (i.e. change http to hXXp) to prevent others potentially becoming infected please?
-Scott-