Since Ubuntu 14.10 came out, I have not been able to install the fglrx drivers. It always fails at the kernel module portion. Currently I'm running Ubuntu Gnome 15.04 (though I've also had this fail in standard Ubuntu as well). The only trick I know for installing the fglrx driver is that there must be a soft link in /usr/src/ called linux, and it must point to the headers directory of the kernel in use. I have verified that this is the case, and am still stuck. I am not using any custom kernel, just whatever the Ubuntu team sees fit to give me. Attached is the log, below is some info about the system.
Linux machine_name 3.19.0-18-generic #18-Ubuntu SMP Tue May 19 18:31:35 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux