Cycles OpenGL

I recently updated Blender (to 2.65) and now cant turn on OpenGL as i could in my previous version (2.64a)
I searched for a solution and found nothing,didnt find anything in Patchnotes either.
With CUDA sometimes it isnt rendering because “Cuda run out of memory” or something like that.
Any solutions ?

Your GPU doesn’t have enough memory. Either get a more powerful nVidia GPU or reduce your scene complexity.