No problems here with 10.3
Win 7 64-bit
phenom II x4 965
radeon 4870x2
Could have been a bad driver install. Did you also install the game profiles? (listed under all operating systems on game.amd.com drivers section)
If worst comes to worst, you may have to use driver cleaner or some such utility. But, it worked out of the box for me. Just ran the installer over top 10.2
Edit: Yes, FarCry 2 is a mess of black boxes popping in and out many times per second. SH5 works good though
Edit2: Far cry 2 works good when I changed edge detect to box AA