AOL still blocks Reverse DNS after it's setup

[AVB]

I set up Reverse DNS for my mail server with zoneedit (who supports my
dns) and with my ISP. If I go to www.dnsstuff.com and Reverse Query my
server then it says it's succesfull. However my mail fails when sending
to AOL. According to AOL
http://postmaster.info.aol.com/cgi-bin/dns_tool.pl   "Reverse DNS must
be in the form of a fully-qualified domain name - reverse DNSes
containing in-addr.arpa are not acceptable, as these are merely
placeholders for a valid PTR record. Reverse DNSes consisting only of
IP addresses are also not acceptable, as they do not correctly
establish the relationship between domain and IP address"

So I am a little lost. Why are reverse DNSes with in-addr.arpa not
acceptable?? I thought thats how they are suppose to be setup. I have
no other option but to set up a record in Zoneedit with the FQDN to
IPaddress.in-addr.arpa PTR record. My ISP has also set up a reverse DNS
entry (which I am assuming is correct cause test are successful). This
is unfamiliar territory and ideas would be greatly appreciated! Thanks