Thanks for the info. I have spent hours trying to sort this out and after uninstalling the driver etc upon reboot the screen became unstable and unable to read! (it was zoomed into the top corner for some strange reason) I tried everything I could think of and in the end reinstalled Ubuntu as it was a pretty fresh install anyway. So I am now back to square one, I have had to reinstall the AMD catalyst control center and the black lines are back up and running!
Output of xrandr
Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 1920 x 1920
DFP1 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 16mm x 9mm
1920x1080 30.0*+ 25.0 24.0 30.0 24.0
1776x1000 25.0 24.0 30.0
1680x1050 24.0 24.0
1400x1050 24.0 24.0
1280x1024 24.0 24.0
1280x720 60.0 50.0 59.9 24.0
1152x648 50.0 59.9
800x600 50.0 59.9
720x576 24.0 25.0 50.0
720x480 24.0 30.0 60.0 30.0 59.9
640x480 24.0 60.0 59.9
CRT1 disconnected (normal left inverted right x axis y axis)
lspci | grep -i vga lshw -C video
Please note that this is on a fresh install with the drivers reinstalled!... according to the Catalyst Control Center the refresh rate is back to 30hrz.
00:01.0 VGA compatible controller: Advanced Micro Devices [AMD] nee ATI BeaverCreek [Radeon HD 6530D]
Thanks so much for the help so far!