No, in the other part of the sentence. It appears a NOT should appear here:
As for your question, you allowed to post it on Flickr or another picture hosting site before the contest, it just should NOT already be posted here on EB or another site as an existing post.
Oh and hey, first post. (Great way to start, correcting a Sith Regulator...I mean, a Regulator that is a Sith, not someone who regulates Sith...I mean...never mind. I'll just force-choke myself to save you the trouble. )