Suggestions for preventing ultra-hi monitor resolution

[Tom Wolfe]

Any suggestions for how to prevent clients from having excessively high 
resolution, e.g. one of my clients ends up with 1920*1440 which is almost 
unreadable.

I tried:

[default]
X_MODE_0 =1024x768

in  /var/lib/tftpboot/ltsp/i386/lts.conf but for some reason this doesn't 
work on this client. I also tried sudo ltsp-update-image in case that 
needed to be done, but still resolution remains 1920x1440 on this client.

Any tips?

Regards,
Tom Wolfe
Morley, AB