I installed shutter yesterday, and it worked great, but I couldn't get it to run today. So I looked around AskUbuntu, and installed the dependencies I was missing and that still didn't solve my problem. Then I type shutter in the terminal, I get INFO: There is already another instance of Shutter running!. I don't see it anywhere and it's not marked as running in my sidebar. I tried uninstalling and reinstalling, purging and installing through the terminal, but nothing helped, I still get the same problem. I am using Ubuntu 12.04