I've just installed Xubuntu 11.04 on my netbook and I'm noticing a problem with the workspace setup. If I log in, I see there's only one workspace specified. If I load the 'Workspaces' control panel widget and alter it to 4, this works fine until I reboot and log in again, at which point the number of workspaces is reset to 1.
How do I get XFCE4 to remember my workstation number preference?