After installing AMDs new driver software, Radeon Crimson, my radar became buggy and glitched. As I turn around the bars disappear and reappear, sometimes with bits missing. The same applies to waypoints and icons.

Interestingly, the radar while wearing power armour is unaffected.

I went back to 15.11.1 and everything is back to normal.

There is a fix. You need to paste the DLLs from 15.11.1 into the Fallout 4 directory where Fallout4.exe is located. You can get the DLLs here - https://mega.nz/#F!8tlAhDyQ!2AkAQukJKAYuIWEzDTGtFA!l4FjhA7R Extract the folder, copy the files inside to the Fallout 4 main directory and you're good to go.

Now the game will run using those instead of the ones in Crimson. If done correctly you should have something that looks like this - http://imgur.com/4Pmhp0U

Credit to PrMinisterGR on the Guru3D.com forums (http://forums.guru3d.com/showthread.php?t=399547) and to xAcid9 on the LinusTechTips forums for pointing me in the right direction (http://linustechtips.com/main/topic/491366-amd-radeon-software-%E2%80%9Ccrimson%E2%80%9D-1530-releases/page-6#entry6594884).