This is great. Synaptic was locked up because it opened up a dialog box under the main window, that prevented the main window from functioning until it was answered. The dialog box was to notify me that the database files were older than 48 hours, and waited for me to click OK. As I could not minimize the main window, it was impossible to get at. And when I killed synaptic, it was killed too. I'm not really sure how I got at it.