TwitterFeed has been failing for me and it only works manually. So, I decided to try on FeedBurner. Below are the critical steps to set up FeedBurner to redirect your post to twitter
1. Go to http://feedburner.google.com and enter your blog RSS feed in the text field. Then, just follow the wizard
2. Click on Publicize tab after the wizard setup. Create a twitter account linkage via Add a Twitter account. Click save at the bottom
3. Click on Edit Feed Detail link, look at the feed address and copy it down
4. Go to your Blogspot setting, click on Site Feed tab. Enter your FeedBurner's feed URL at Post Feed Redirect URL. Click save.
Now, you can try posting a blog entry at your blogspot site. It should be reflected in your twitter.