Created attachment 53630 [details]
Screenshot of the issue: http://www.zimagez.com/zimage/screenshot-111711-123012.php
The yellow/black stripes are *not* part of the image (it's a screenshot of a window, you can see a bit of it at the far right). The stripe pattern appears when moving/panning/zooming the image (may take a bit of effort).
Moving/zooming/causing repaint makes them go away again. I recognise them as one of the possible fill-styles, although that may be a coincidence.
Updating from aac022cbb3342e7027301a3f8c9add8929edbad6 to the latest git (eb6148a36a318eb0b4aad865c34b50fedf4b709e) does not alleviate the problem.
Window manager is xfwm4 with compositing turned on. Turning compositing off does not alleviate the problem.
Hardware is Dell XPS 15 (L502x) with:
00:02.0 VGA compatible controller: Intel Corporation Device 0116 (rev 09)
[ 13.803] (II) intel(0): Integrated Graphics Chipset: Intel(R) Sandybridge
kernel: 3.1.0 (vanilla)
gimp: media-gfx/gimp/2.6.11-r5 (gentoo)
Forward duping for the reproduction steps.
*** This bug has been marked as a duplicate of bug 43134 ***