With the 310.xx and 313.xx driver series (incl. 313.18), a very old problem has returned: A switch from X to the tty console resets the console font. Setting the font again works but if you switch back to X and repeat the procedure (X -> console), the font is reset again.
This can also easily reproduced from the console itself.
(1) Make sure the nvidia module is not loaded or unload it
(2) Set a console font (terminus ter-116b)
(3) modprobe nvidia
(4) the screen flashes for a fraction of a second to black
(5) the console font is reset
Here my bug report, if required:
Hope this helps in narrowing the bug down.
Thanks a lot in advance…