Are you saying that some IP addresses in that range are being allowed?
The mechanism I use looks like this for an internal use only site:
Deny from all
Allow from nnn.nnn.nnn # Work network
Allow from nn.nn.nn.nn # Boss’ house
Allow from nn.nn.nn.nn # My house
And it works. I have the deny/allow in proper order, and no subnet mask for work’s IP address range.
For yours, I’d make it look exactly like:
deny from 78
deny from 88
allow from all