Hi,
I can confirm this bug with an up to date Jessie on a Clevo W950TU laptop (also known as Genesis V from PCSpecialist). Currently KDE 4.14.2, kernel Linux 3.16.0-4-amd64.
Running Jessie, Debian 8.1. Installed as wheezy and then updated to Jessie (a couple of weeks before Jessie became stable).
Can also confirm that I didn't have this bug on Kubuntu (as of a couple of months ago, with the same laptop.
Happy to help diagnose this if anyone has suggestions; haven't tried the workarounds yet, but will do, thanks!
Cheers,
Nick