I set up Twitter Tools plugin to display tweets on my side bar and to be able to post tweets from the sidebar.
I entered the bit.ly information so it would shorten URLs automatically without me having to go to bitly to shorten the link, copy, then come back and paste the bitly link in to complete the tweet.
So I go to enter a tweet from my sidebar. The problem is, I write a tweet, say 110 characters long, then paste the long URL hoping to have it shortened into a bitly link. The problem is that when the URL is pasted into the field, it only allows up to 140 characters. So in this case only the first 30 characters of the URL were pasted in and the rest was chopped off, resulting in a broken link.
It then shortens this half-link into a bit.ly link but as it was only half a link it returns a 404 error.
I am sure that when I installed and used this yesterday it was allowing more than 140 characters and would then display as a negative amount of characters if I went over 140. This is not happening today for some reason.