On logging in I decided to try try an Xfce-session instead of my usual Xubuntu-session.
When I opened up Firefox in Xfce-session I was asked if I would like to make it my default browser, which I thought strange as it was already my default browser in Xubuntu-session and I had thought Xfce-sessions would use the same .mozilla dir and settings etc.
I then logged back into Xubuntu-session, and everything now looks a bit blurry, text looks different, Firefox asked me again if I wanted it to be my default browser although it still has my bookmarks etc, I have 4 virtual workspaces instead of 2, the icons for all different types of files are different, and my windows look different than I left them: the title-bar looks different than the default, and I didn't have an option to minimize the window to the title-bar etc. please see screenshot.
If all these things have changed, more possibly has. I didn't even go near any options in the Xfce-session. What happened, and how can I fix it without a fresh install of Xubuntu 11.04?
Fixed by logging out, ctrl+alt+f6 to bring up a TTY, logged in and executed:
When I booted back up and logged in everything Xfce was back to Xubuntu 11.04 defaults.
sudo rm -rf .config/xfce
sudo shutdown -g now
*I think you can probably just log back in but I chose to reboot.