Hey you may have already figured this out, but when you receive a "transaction broadcast error" when trying to post a post, it typically has actually posted. I should mention that there are many 3rd party websites that you can use to do your Steem-ing, busy.org being the most prominent, and to my knowledge every single one of the 3rd party websites works better than steemit.com. I have never had a single issue on busy.org with transaction broadcast errors or any of the other hosts of problems that steemit.com has. Just a tip :)