Being sincere, I was skeptical about your suggestion, anyway, reading my Xorg.0.log again I've found
Code:
(II) LoadModule: "dri"
(II) Loading /usr/local/lib/xorg/modules/extensions//libdri.so
(II) Module dri: vendor="X.Org Foundation"
compiled for 1.4.0, module version = 1.0.0
ABI class: X.Org Server Extension, version 0.3
even if in my xorg.conf I have
So it seems that xorg-7* loads dri even if it's not listed in
Section "Module". Now I've added
Disable "dri" in the same section and the message doesn't appear anymore.
The problem appears randomly and I can't find an action to trigger it, so only time will tell if that is the solution.
In the meanwhile...thank you very much!