Yes, it is still an issue on ubuntu 13.10. (No proprietary NVidia driver installed.) I will test the problem on the latest development version of ubuntu.
The issue is worse than you might expect. I often need to read and edit documents and those use a white background (typically PDF documents). The brightness is so high that it turns the notebook almost unusable for me. Please note that the HP ZBook series is rather new (selling started about September 2013) and this might be the reason why not so many people complain about the brightness bug. Nevertheless, the other user confirmed the issue very recently (25th December). -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1257766 Title: can not reduce brightness on HP ZBook To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1257766/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
