Rated 5 out of 5 stars
This is an awesome extension that adds the sidebar functionality of Opera to Firefox. This has been a favorite Opera feature and I thank the extension author for taking the time to create it!
@emarell - You may want to check and see if you have extension conflict. I installed v0.2.8 and have no issues as you reported - vertical bar retracts and opens as always. Just a thought as I have run into issues like this before.