Do you also get crashes if you use any other tool like the pencil or brush?
This might be a dublicate of the following bug:
https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/1021517
Can you check your XorgLog.txt or XorgLogOld.txt in /var/log/ and compare it to the one in the link?
Do you also get crashes if you use any other tool like the pencil or brush?
This might be a dublicate of the following bug:
https:/ /bugs.launchpad .net/ubuntu/ +source/ xorg-server/ +bug/1021517
Can you check your XorgLog.txt or XorgLogOld.txt in /var/log/ and compare it to the one in the link?