I really want to share this experience with the forum in case some other poor sod has the same issue I had this morning.... I was thoroughly pissed off this morning when, upon starting my laptop, my XFCE session went all Anders Breivik on me. The work space chooser was only displaying one work space, windows could not be maximized or minimized... in short a ghastly mess... in my haste I was going to re-uninstall XFCE. Googling a bit I finally found a more elegant solution - simply remove the session cache! In the /.cache/sessions sit a number of xfce files. Remove them and you are back to 'normal'. Also, before login out or restarting make sure that you untick the "Save sessions for future logins". It is still a mystery why the session got corrupted.... I am just pleased I got my XFCE working correctly again... All the best! Keep on trucking!!!