I'm not sure if this will help you in any way. I first tried to start my test Mint with the installed driver normally and got my black screen. After a reset I started it with GNOME classic. And now I have a Xorg.0.log and Xorg.0.log.old. As I deleted all Xorg logs before the .old log should be from the black screen session and the other one from the working GNOME classic session (unless my understanding of the Xorg logging is wrong - which could be very easily :p).
Both logs nearly don't differ. The .old has only one line more (drmOpenDevice: open result is 12, (OK)) but I guess this is irrelevant.
However, here are the links (they will expire in one month): http://pastebin.com/7g3NjECV http://pastebin.com/CThiAgCh
Mybe also noteable (I first recognized it by reading the log) I don't have a 16:9 resolution in GNOME classic anymore. But I'm sure there was one before I installed the driver (1920x1080).