we're not talking about forward and reverse DNS, you moron. we're talking about an RBL, specifically a dialup/dynamic/dhcp (DUL) list.
Was the dialup/dynamic/dhcp address not determined by an improper reverse DNS? Specifically, host 213.162.113.17 reversed to pigeon.adsl.metronet.co.uk I thought it was a natural transition. Or do you actually perform a RIPE database lookup on the IP when you block from dynamic IPs?
Either way, Forward/Reverse DNS is relevant for those of us that filter by it.
-eric