Turns out it didn't quite fix things.

Cgminer now detects the cards but it just generates Hardware errors.

Not sure what version as it didn't say, just said 'Experimental Beta Drivers' so i guess it was 13.3.
Probably the version listed here is what it installed:
http://support.amd.com/us/gpudownload/linux/Pages/radeon_linux.aspx?type=2.4.1&product=2.4.1.3.42&lang=English

So far Version 13 either fails to compile correctly or generates hardware errors in both Ubuntu 12.04/Xubuntu 12.04
Standard flgrx (i assume these are the open source drivers) failed to work.

So i'm working my way down this list now until i find one that does work:
http://support.amd.com/us/gpudownload/linux/previous/Pages/radeon_linux.aspx