Ubuntu 12.04
I bought a Sapphire Radeon HD7750, downloaded the latest drivers "amd-driver-installer-catalyst-13.3-beta3-linux-x86.x86_64", finally got them compiled and installed with dpkg -i.
i tried to launch darktable and get this warning

darktable
Setting of real/effective user Id to 0/0 failed
WARNING: Not loading blacklisted module fglrx
FATAL: Module fglrx not found.
Error! Fail to load fglrx kernel module! Maybe you can switch to root user to load kernel module directly
X Error of failed request: BadRequest (invalid request code or no such operation)
Major opcode of failed request: 156 ()
Minor opcode of failed request: 19
Serial number of failed request: 12
Current serial number in output stream: 12
I tried modeprobe fglrx get a warning
sudo modprobe fglrx
WARNING: Not loading blacklisted module fglrx
FATAL: Module fglrx not found.

I found a fle called fglrx.conf containing
# This file was installed by fglrx
# Do not edit this file manually

blacklist radeon
alias fglrx fglrx
alias radeon off
alias lbm-radeon off
Where do I go from here?