Have I been banned?

Looking at all your submissions,

http://news.ycombinator.com/submitted?id=b09

I'd guess that most of the submissions were flagged dead, because readers who surfed by them thought that they were low-quality links. Try submitting some higher-quality links (look at the main page for examples) and see what happens.

news.yc appears to dislike self promotion - go into your profile and turn on ShowDead and you can see that of the seven links you submitted, four were flagged and killed.

If it isn't self-promotion, then you would be better served by submitting the original story link rather than the excerpt surrounded by ads that links to the original story.

No, your account is not banned, your submissions are just low quality and are getting killed by other members flagging them.

Censorship ftw