Seems that there is a fix that works more properly!
It's similiar to the "rift.exe" solution, only a different profile, what actually happens is Catalyst applies different options to the application:
Instead of changing the "Crysis2.exe" to "rift.exe", set it to "FEAR.exe". This worked pretty good for me!
* No more flickering
* Maximum framerate (Crossfire enabled)
* For AMD users
But there may be a little disadvantage for this fix: slight mouse lag. Just like in V-sync.
I'm calling out all other users to spread the word to other AMD users to finally play Crysis 2 decently, I hope this works for the most of ya!