graphics issue with install but live USB works

[halt]

I flashed a USB stick with the live DVD image and I can successfully boot from it. The desktop displays correctly at the full resolution of my monitor. So I installed to the hard drive. When booting I can get into the grub menu, and I can boot from the hard drive install, but at the point where it switches to the graphical display the display gets garbled and I can't get any further. I think this is because my monitor is difficult: it only supports two resolutions, 2560x1600 and 1280x800. When using it with windows or Mac OS, setting the display to any other resolution (even very standard resolutions) has the same effect. I'm not sure exactly what stage in the boot is causing the problem though. I've tried different configurations of the grub command line, including adding "nosplash", "nomodeset", "xforcevesa", and setting "gfxmode" to one of the supported resolutions. Whatever I do I get the same results (although the pixels on the garbled screen looks like they reflect the resolution I'm choosing in the file).

It's a nvidia card, and the computer was linux-certified (and came with a different linux distro preinstalled, although I overwrote that with Mint) so I think everything should work out of the box except the monitor. And it works just fine with the live USB stick... so how do I get the same results out of my permanent install?

thanks!

[kukamuumuka]

Copy live USB´s /etc/X11/xorg.conf file to the installed system´s /etc/X11 folder

[halt]

Thanks for the response! I ended up reinstalling from the live USB but while connected to the internet this time, and it works OK now. I guess for some reason being able to update the graphics drivers fixed the issue.