The query to the URL shortener API failed, and your URL was not shrunk…

I am using WP-to-Twitter and have been using the bit.ly shortener. It was working fine but now I’m getting the following error message:
The query to the URL shortener API failed, and your URL was not shrunk. The full post URL was attached to your Tweet. Check with your URL shortening provider to see if there are any known issues.

I found an earlier closed thread that said it had a solution and that was to use the Bit.ly user name and not your Twitter user name in the BIt.ly settings box, but I am already doing that. So that solution doesn’t solve my problem.

Does anyone have another solution that might work?