Well I'm having big problems here as well. When I installed the - apparantly tested - nVidia drivers, the resolution went back to a horrible 640 x 480 or even smaller. You can't almost navigate at all.
Just like the OP, I can't change the resolution and then select "Apply" or whatever it should say there. I see resolutions up to 1024 x 768 is supported, but when I try to do iaculallad's command in the terminal, this comes back:
Or change 1024 for any number.
bash: syntax error near unexpected token `1024'