Update, seven years later: Not only has that problem not been fixed, now it doesn't work at all. This is very disappointing because it's so good when it works! But between that and the inability to export my bookmarks (despite how the site says it has that functionality), this isn't worth it anymore.

Other reviews have mentioned problems, but I'm most frustrated with the pop-up window. If I click away from it, whether to highlight other text or to scroll down, it disappears AND erases everything I'd already added to that annotation. The main description field has been reduced to a single line, making it difficult for me to see the description I've added.