Um, the PID lock is set when a process is running that needs exclusive access to its control files. Typically, "update" is one such process. If you have "automatic update" or "check for available updates" turned on, the update program will be started when you boot, and run until it finishes updating your system or identifying pending updates. While it's running, you can't run a manual update.
So, either wait 'till your automatic process finishes, or turn off automatic updates. (Note that your copy of audacity may be automatically updated if there is an update pending for it.)