Xfce4 suddenly doesn't start properly
I've been using Xfce4 for a little while now, and I really like it. Earlier today though, a problem started occuring. While I was working, I noticed the launcher bar lock up, although Gaim and Evolution (the only things I was running) carried on just fine. The right-click menu also failed to appear, and so lacking any way to log out properly, I switched to a text console and powered down the system.
Once I rebooted, and tried to log in again, the Xfce4 startup screen displays correctly, then the Gaim and Evolution windows reappear (I set the option to save sessions on). That, and the taskbar, is all though. The desktop background remains a plain grey, the launcher bar fails to appear and right-clicking on the desktop does nothing. Rebooting doesn't help.
I've already tried removing the ~/.xfce4 directory, which didn't help (and this hasn't been recreated even after several login attempts), and I even tried reinstalling all of the Xfce4 packages. Still nothing.
I have no idea which configuration files (if any) would be useful for diagnosing this. If anyone has any ideas where I can start looking to fix this they will be greatly appreciated.