I have the same problem. The only way I can see the map is to turn of "Enhanced Water Effects" and "Landscape Bumpmapping" off in the graphics settings to see the map then turn them back on after.
Edit: I made a ticket on January 31st but have not yet received a reply yet. Im using Windows 7.

Probably won't help, but just in case - forcing anti-aliasing through the drivers (and disable in-game if it's enabled) - this worked on one or two other games for me.

Tried Giants Hook. It at least made it so the fog of war lifted when i walked around, but I still get the giant diagonal light and the map is broken, unless I turn off Enhanced Water Effects. I sent in a ticket, it seems to have just faded away.