Did you turn off ‘Use OpenGL for all rendering’?
Edit with respect to the comment:
Sorry! I put it wrongly. My intention was to give a hint that an OpenGL issue might be the cause of the malfunction, and to turn OpenGL rendering OFF to get things working better. I have no idea concerning another possible cause…
…except: A corrupted user profile is known to be a possible cause for very strange behaviour of LibO. Try to reset your user profile. Be careful and follow the steps as described here.
Edit with respect to the comments: Sorry! I have no idea beyond this.