Comment 20 for bug 1518597

Chris, missing informatio - does the system show the same errors when you deactivate the effects?

Anyway, as far as I remember, the "Blur"-effect was always buggy. Try to deactivate it.

The kubuntu-backports-ppa provides fixes which will not arrive through the normal backports-channel. [1] [2]

[1] (http://wire.kubuntu.org/?p=419 - title: KDE 4.14.3 Bugfix release for Kubuntu Trusty (14.04.3 LTS) is now available.)
[2] (https://launchpad.net/~kubuntu-ppa/+archive/ubuntu/backports)

With regards to the age of the integrated graphics I would not assume it's capable of running OpenGL 2.0

If U suspect Abobe-Flash to have a cause make shure U run the newest version by activating the "Partners"-repository, also look at the "right-click options in embedded video. Best suggestion here to try2avoid Flash (make use of HTML5!)

> ... I don't think I did anything that I
had not done before... Crazy...

Make also a physical inspection of the motherboard and it's components inspect vents, Kondensators, run a RAM-check (due to the age). A fact: if effects appear after a while running, this may actually speak for HWE constraint. Since other know serios causes were exluded.

<OT> I'd actually build a new tiny new PC 4myself & KDE5 a while ago, Processor has socket AM1, CPU 4x1.3 GHz - all2gether less than 200$ - (I do not play games, though) <OT>

Excuses 4 late reply.