Just a quick note on a small Codeplex project I am starting. After having done some BizTalk RFID work, I found the supplied code sample for a duplicate eliminator to be an excellent example of a custom event handler, but a poor implementation of a duplicate tag eliminator. This codeplex project is a little better thought out dupicate tag eliminator with a few added features.
Go take a look if interested and let me know what you think: BizTalk RFID Better Duplicate Tag Eliminator