Each time you suggest a site you agree that you've read and understood the submission instructions at
http://editors.dmoz.org/add.html . Presumably you missed the bit that reads:
multiple submissions of the same or related sites may result in the exclusion and/or deletion of those and all affiliated sites.
However, we recognise that everyone is human, and people are bound to make mistakes. So one or two duplicate suggestions won't get you labelled as a spammer. (Obviously we won't be saying exactly how many will though...) Some suggested sites were lost in the crash, but as long as you've suggested your site some time in 2007 there's no need to do so again.