Thank you fellows. On closer inspection, there is a wee button entitled 'Enable Wireless Access Point' which will only allow cabled connections to run when unchecked.
I might try the more subtle 'Wireless Station Access List' method when I'm a bit more familiar with IP addresses, MAC addresses etc. But am I right in thinking that the MAC addresses shown as connected do not change?
It still doesn't solve the problem of the mobile phone - but reporting it as stolen sure does!!
Roll on July!!
Cheers all,
mcdhu