System freeze on ejecting USB stick

[ian_r_h]

Hi, all,

I seem to be hitting another Linux Learning Curve(!), and need to ask for a bit of help, please.

From what I've read it looks like I should try the following:-

• Boot from live DVD and run the memory test, to verify that it is not a memory hardware issue,
  
• Boot from live DVD anyway, and check again that it isn't a more general USB port/sticks issue,
  
• If it freezes again when ejecting USB stick in Thunar, try restarting X (question on this below),
  
• If it freezes again, can I open a virtual console (question on this below),
  
• Can I CTRL-ALT-DEL from laptop internal keyboard and restart,
  
• Try manually dismounting from terminal instead of Thunar and see if it still freezes (I'll close Thunar first).
  
• Hold SHIFT(?) on boot at try an earlier kernel if available,
  
• Try an earlier restore point.
  

But I need a bit of help with some of this please.

The Ubuntu keyboard shortcut to restart X is CTRL-ALT-BACKSPACE.  However, this is disabled by default in Ubuntu but re-enabled in Gnome in the keyboard settings:-

• Is CTRL-ALT-BACKSPACE enabled or disabled in LL3.8?
  
• There seems to be no setting I can find in the keyboard settings in LL/XFCE to enable the shortcut if it is disabled, in which case how can I enable or how do I assign a shortcut?
  
• How could I try restarting X should I be able to open a virtual console?
  

It's butting up against my terminal command knowledge at that point.

Thanks,
Ian