Since I've updated from 12.10 to 13.04, desktop environment freezes on each startup. My GPU is ATI Radeon HD 4670 (RV730), driver
fglrx-updates is installed, Linux
3.8.0-19-generic, 64-bit system. Should I use another driver to fix the problem? Had anybody have the same problem?
Parts 1-3 are suggesting Radeon HD 4670
My answer comes 1 month later after the question but if you haven't cleared the issue meanwhile, maybe this helps.
As long as the AMD Radeon HD 4000 Series are concerned, AMD isn't providing support beyond specific Kernel version (3.4) and Xserver version (1.12). They are considering this cards legacy.
You can read about this in the footnote of the official AMD drivers download link for Linux (x86/x86_64): http://support.amd.com/us/gpudownload/linux/legacy/Pages/legacy-radeon_linux.aspx
This actually means that if you want 3D acceleration in Ubuntu for AMD Radeon HD 4000 Series you can go as far as Ubuntu 12.04 LTS (that has Kernel 3.2 and Xserver 1.10).
Ubuntu 12.10 has Kernel 3.5 and Xserver 1.13. Ubuntu 13.04 has Kernel 3.8 and Xserver (still) 1.13.
So, even if you managed to install fglrx in Ubuntu 12.10, it doesn't work at all (but at least it doesn't crash your system). On Ubuntu 13.04 things seem to get worse - from your post - with the system freeze.
I know all this because I also have a HD 4670 card and I've tried to install accelerated drivers for Ubuntu 12.10, run into problems and tried to get to the bottom of the issues. I now run Ubuntu 13.04 with the open source drivers for HD 4670.
If up to now it's not very clear: you should remove any fglrx driver from your system as it doesn't really work at all (for all the reasons previously explained) and can only lead (in the worst case) to system freeze. There is no fglrx driver (Ubuntu provided or AMD provided) that supports HD 4670 on Ubuntu 13.04 (or 12.10 as well).
What I suspect first and foremost is that fglrx is creating a custom xorg configuration file [/etc/X11/xorg.conf] on install and "forgets" to remove it on uninstall which will throw your graphics into the woods when you restart.
If you've got the time/mood for it, you can try this:
As you indicate that you actually have a HD 5670, this is a totally different situation.
If you go to http://support.amd.com/US/GPUDOWNLOAD/Pages/index.aspx and put the right parameters (Desktop Graphics, Radeon HD Series, Radeon HD 5xxx Series PCIe, Linux x86_64) you'll see that your video card is still current and AMD provides drivers for it that should work in Ubuntu 13.04 (see the note about Xserver up to 1.13 but note there's nothing mentioned about the Kernel version). There are 2 driver versions: stable is 13.4 and beta is 13.6.
You have 2 options: