Good question. I did notice that some of your recent posts have been flagged for moderation so I just took a look at your account settings and there is nothing unusual there... you have the same access as anybody else who has posted X amount of threads.
The only thing I can think of at the moment is that we use Akismet to try & catch spam bots and those threads are flagged automatically to be moderated for approval. There is a possibility that the Akismet algorithm is kicking in.
When I get home tonight (still at the office right now) I'll check the Akismet settings.