Just a little pet peeve with Bloglines

I love bloglines. I use it every day and usually keep a browser window open to the site. However, lately I’ve noticed that I seem to be getting more and more stories duplicated. I’ll check in the morning and go through all my feeds. Then later on many of the stories that I read earlier will return as new again. Not the end of the world, but a bit of a pain none the less. Is this due to load issues at bloglines? Otherwise a great service.