I'm using the .76 drivers and don't have such problems. Make sure AA, AF, V-sync (in the driver) are set to application-controlled. Once the shaders are compiled and cached (takes a minute or two) the flickering textures/corruption should be gone.
If it doesn't go away, you have most likely a memory leak in the shaders. Please file a bug in the bugtracker at the beta forums.
You can also try to disable the shader compiler by changing this line in the system.cfg
r_ShadersAsyncCompiling = 1
r_ShadersAsyncCompiling = 0
But remember the compiler is activated by default to find and report bugs/shader memory leaks in the first place.