I too ended up closing a sprint by accident. As a new user sometimes things like this happen. (Whether or not they are part of the accepted scrum flow…)
I was about ready to give up on icescrum because of this one frustrating issue… I ended up closing down the server and hacking the prodDba.script on the back end… (You need to set the status and close dates. It’s not an easy thing to do. If your project is bigger then my little test project it may not be doable.) If you are using a different DB you may have to use SQL. (Shut down the icesrum webapp first and make a backup to be safe. It took be several tries to find everything…)
Maybe this is something that needs to be put in as a user story to the icescrum app that the icescrum team is using to develop icescrum… 😀