Created attachment 121882 [details]
Log from Xorg with default options

I noticed some texts were looking blurry depending on my MATE Desktop theme and
filed a bug report to MATE team
(https://github.com/mate-desktop/mate-themes/issues/104). We discovered that
the problem is that my GFX card renders text shadows incorrectly.

Adding this option fixes the problem:
    Option "ShadowPrimary" "true"
This has a side effect of disabling pageflipping. However just disabling
pageflipping alone does not fix the problem.

Also if I turn off acceleration completely with:
        Option "Accel" "false"

The problem also is fixed.

Attached: Screenshot and XOrg log of when the problem appears (default options)
and when it is fixed (enabling ShadowPrimary)