Comment 8 for bug 1509721

José Vidal, thank you for reporting this and helping make Ubuntu better.

Could you please run the following command once from a terminal as it will automatically gather and attach updated debug information to this report:
apport-collect -p xorg 1509721

Please ensure you have the package xdiagnose installed, and that you click the Yes button for attaching additional debugging information.

When reporting xorg related bugs in the future, please do so via the above method. You can learn more about this functionality at https://wiki.ubuntu.com/ReportingBugs.