Ok, so I have Linux Mint 7 "Gloria", using kernel 2.6.28-11.
I got a new GeForce 8400GS and replaced my ATi pile of sh*t with it
no problem, Mint starts up fine as if nothing happened.

Install NVIDIA drivers following the instructions on these 2 threads:
http://www.nvnews.net/vbulletin/showthread.php?t=72490
http://ubuntuforums.org/showpost.php...08&postcount=6

Everything seems fine, so I reboot and all seems fine, except when
I try to play music or a video I get no sound at all. I'm fairly
certain that something in the first links instructions (the Ubuntu ones)
removed something it shouldn't have, but I have no idea what to look
for.

Any help appreciated, thanks!


EDIT:
Ok, it seems my sound cable has broken during the installation or
something, my headset works fine on my computer. What timing again.

Check /proc/asound/cards and see which card is 0 the default card. A lot of video cards have audio on them now. Since HDMI transports audio as well as video. Various ways to re-index the modules to sequence in a specific order, or to have the applications choose a particular device. Which is probably what changed in the install with the introduction of a new device.