How to get rid of session 'memory' in xfce for a clean restart?

[Chris G]

I'm running xfce4 version 4.4.2.1 on xubuntu 8.10.

The latest xubuntu upgrade has, for some reason, stopped X starting up
properly.  Looking at the .xsession-errors file I think this *may* be
due to the restart (after the kernel upgrade) trying to restart some
applications that have problems.

How do I get xfce4 to do a 'clean' X startup with no session 'memory'?
I currently don't even get to the login screen so I can't do it from
there, presumably the restart is trying to give me back my session
exactly as it was (and failing).

-- 
Chris Green