Xorg eating the CPU

[MR ZenWiz]

Since the last update last night, my laptop is running 60-80% CPU
intense processing.  According to top, this is due to Xorg (although
earlier today before I rebooted, it was system-udevd that was eating
the CPU).

This is new and disrupting all the processing on my laptop.  The only
change I made was to install the nvidia driver (361), which is the
correct driver for my video card and an older version of which I was
running on 14.04 before upgrading a couple of weeks ago.

Any suggestions on what to look for?

Thanks.
MR