changing terminals

[MICHAEL WEAVER]

When I login to Ubuntu on my laptop, I can't seem to change terminals 
using the CTRL ALT F keys.
I can run gnome-terminal for running Orca but when I try CTRL ALT plus a 
function key ie F2 my PC seems to lock or I lose speech.
Why is this happening?
Could it be because I only have an Administration account on my laptop 
or lack of memory on the machine?