it looks like your having an issue with the wildcard mask "WM"... Let try to make this as simple as possible....

if you have the following

192.168.1.1 with a WM of 0.0.0.0= your saying everything need to match so the only address that would work is 192.168.1.1

I hope that makes sense.... Now..

192.168.1 0.0.0.255= 192.168.1.0 -255 why because... let me explain it this way

a 0 in the wildcard mask means that must match so we know we have

192.168.1.0 with the first 3 octants matching so that means 0.0.0 and the last one lets say it is a /24 that is 255 so it would be 0.0.0.255 because the last octant could be anything from 1-254 I hope this makes sense it is late and I am tired if not PM and I will explain it better