I'm also on Thinkpad T520 with Ubuntu x64 15.04. I tend to use an external Logitech M705 mouse with a Unifying Receiver -- but the Logitech might just be a casualty.
This was not a problem until I moved to 15.04 -- I did a bare-metal install to eliminate system cruft, but retained the home partition.
I'll try to file a report when the problem recurs.
I'm also on Thinkpad T520 with Ubuntu x64 15.04. I tend to use an external Logitech M705 mouse with a Unifying Receiver -- but the Logitech might just be a casualty.
This was not a problem until I moved to 15.04 -- I did a bare-metal install to eliminate system cruft, but retained the home partition.
I'll try to file a report when the problem recurs.