squid acl entries

I am having problems excluding by IP address. This is
to limit local usage only, so all users are on the same
subnet. I enter the following:

        acl all src 192.168.253.193-192.168.253.224/255.255.255.0
        acl all na1 192.168.253.2-192.168.253.192/255.255.255.0
        acl all na2 192.168.253.225-192.168.253.254/255.255.255.0

        http_access deny na1
        http_access deny na2
        http_access allow all

...which somehow disables all in the range "all" and otherwise.
If I leave out the na1 & na2 lines, the entire net is allowed
based on src address. Do I have the syntax wrong?
Received on Tue Nov 04 1997 - 20:14:52 MST