Accept/Deny incoming network connection for apps already accepted/denied

Question

i am constantly getting the dialog box to allow/deny incoming network connections for applications that i launch on my MBPro, even though these programs have already been allowed or denied. this causes multiple entries for the same applications in my firewall advanced list. each time i accept or deny, a new entry of the same program is added to the list. as an example, for Excel i have 5 entries - 2 that allow incoming connections, 3 that deny. the same goes for apps like itunes, word, nleac, and others.
if i delete these extra entries, they just get added to the next time i launch the program.
i've tried the remedy suggested by the macfixit forum (http://reviews.cnet.com/8301-13727_7-10330466-263.html) of deleting the firewall preference file "com.apple.alf.plist" and performing a disk permission under Safe Mode - didnt help.
looking for new suggestions. incidently, this wasnt always the case and other than upgrading to snow leopard, i cant specifically recall a change that started this problem.

Answer 1

i've been doing that for some time now, as this problem has been going on for months. even after i delete all of the programs that have multiple listings (and the key word there is ALL because basically every program that wants access has multiple listings here) the list gets re-populated the next/every time i launch that application. even if i later deny an application's request after accepting previously, they'll be multiple listings for that app - including listings to Allow and listings to Deny - for the the same app!!!