How do I get Duplicate Message Detection in Exchange 2007 to work correctly?

I have a question on Duplicate Message Detection in Exchange 2007.  Here is my issue / question.  We are using a barracuda spam firewall that scans all mail and then passes non spam mail to exchange 2007.  We had an issue in where symantec endpoint virus defs became corrupted and mail flow stopped for a few hours last night until that software was uninstalled and reinstalled.  A few of our users complained of missing messages from late last night which is when our endpoint corruption occurred.  I was able to figure out that when I tried to resend those missing message from our barracuda device to exchange they were getting flagged as duplicates and were not getting delivered to outlook.

Here is what I tried to do to fix it?

http://technet.microsoft.com/en-us/library/dd577073%28EXCHG.80%29.aspx

DeliveredTo Expiration in Hours was set to 1 Hour
DeliveredTo Cleanup Interval in Seconds was set to 900 seconds or 15 minutes

I did not reboot the server after the reg key additions.  I just restarted system attendant, transport, and info store services.  

I waited about 2 hours and try to redelivered some message to myself as a test but was unable to do so.  The messages make it to exchange as I can see them in the Message Tracking Results with Event ID Duplicate and source Storedriv.  I have attached a screen shot of that to this question.  

Does anyone have any idea on how I can get this to work?  I would like to be able to re-deliver messages whenever I want to.  I would also like to add that this works fine for email older than 7 days.  (tech net article - By default, the store keeps track of duplicate messages for seven (7) days (168 hours).  

We are using exchange 2007 ver 08.02.0301.000 running on 64 bit server 2008 enterprise sp2

Thanks.
exch-dup-screen-shot.jpg