At thoughtbot, we use 37signals' Basecamp for project management, and Campfire for interoffice chat. But sometimes, circumstances beyond our control compel us to participate in Atlassian's JIRA software. JIRA's todos are called issues, and require certain permissions to mark issues as complete, resolved, confirmed, etc. I don't have permissions to do any of these on many of the issues I'm assigned, and so my only option is called Cancel, which, interestingly, marks the issue as Fixed. I think the experience of working with JIRA, and all of Atlassian's enterprise software, can be summed up by this screenshot:
Update: Apparently this instance of UI insanity was not truly JIRA's fault, but the client's for specifying Cancel as an option in their workflow. Fair enough! For something this bizarre, it takes two.