Partial Mouse Lockup

[Thomas George <lists@tomgeorge.info>]

Mouse clicks don't work though mouse moves the pointer.

This happens infrequently, once in a day or two. I am using two pc's, a 
raspberrypi and a Ubuntu Studio each with its own Logitech usb keyboard 
and have experienced  this problem on both systems.

I have tried to recover with various keyboard entries - ctl-c, cti-d, 
esc, q and by disconnecting and reconnecting the keyboard. Nothing but a 
reboot solves the problem.  I use ctl-alt-f1 to open a terminal, sign in 
and enter shutdown -r now to do this. There is no problem with the keyboard.

Is this a known problem? Is there a known solution?