The Lock Step dialog box warns you when you have initiated an action that requires Process Tracker to lock the current work item. Before locking the work item, Process Tracker retrieves the most current information. The work item remains locked until you explicitly unlock it.
You can turn this warning off by checking the Don't ask me again checkbox. If you turn the warning off, Process Tracker automatically locks the necessary work items as needed. The warning automatically reappears the next time you start Process Tracker.