You missed the important * of the end as that is a wildcard for everything behind the hi5.com/
You could go a step further and use this text string to block the URL *.hi5.com/* the first asterisk * blocks sub domains e.g. subdomain.hi5.com/webpage.html and you don't have to enter the http bit.
The first one you added or the one Tech suggested wouldn't cater for the sub domains and they would get through.
However, I believe you should use your firewall for this kind of blocking as with wildcards used in this way the web shield might just be slowed checking permutations of the wildcards.