pop3 / reverse dns help

[nitsujw]

i have postfix with cyrus-imap and cyrus-sasl and bind dns. everything was working great until one day i connected and it took me 5 minutes to get into my mail acount through pop3. some people say it was becuase of reverse dns and it needing to be disabled, but there is no where in my cyrus.conf or imapd.conf that specifies anything about reverse dns. if anybody has a suggestion i'd appreciate it. thanks