Twitter blocks duplicate Twitter status updates, so autoposts for Twitter is a bit pointless. There needs to be a workaround.
An alternative is to request a new short url each time for the auto post. I use a custom Bitly url. Is there a way for SNAP to send an autopost of the same tweet, but use a different short URL each time?
If not, then SNAP for Twitter is useless when it comes to autoposts. Twitter will always block identical tweets.