to get nvidia driver, in a terminal do (you have to be in init mode 3 and with root as current account):
1) ftp download.nvidia.com
2) it asks u for an user, write anonymous
3) and a password, your email
4) do the CD command to get to
wich is the latest version for x64 linux versions
5) do the GET NVIDIA-Linux-x86_64-100.14.23-pkg2.run while you are in the directory from step 4
6) when u finish downloading the file, do the BYE or EXIT command to end the ftp session
7) sh NVIDIA-Linux-x86_64-100.14.23-pkg2.run (then the nvidia setup will ask you some questions, answer yes to all of them)
8) restart your computer, if u want, begin with init mode 3, do a startx, if it goes well, restart and boot in mode 5 (X11).
and about ur post:
If your linux freezes even in mode 3, it means some service is causing a problem, couldn't tell u the reason because I'm a
too. But if you can do a startx it means this is no video related, but I suggest installing the nvidia driver to get 3d support fully enabled.
Sometimes I get the same freezes during two or three different services, while shuting down, like smart-something and cups I think.