I can confirm the same issue with my system, using an NVIDIA 660 GTX, running Mint 17 with Nvidia drivers 331.38. Turning off FXAA didn't work for me. None of the settings made a difference. The only thing worked was removing the NVIDIA settings file as suggested by xavier zinn. Now everything seems to be running flawlessly.
** Attachment added: "bug report, after deleting nvidia settings" https://bugs.launchpad.net/ubuntu/+source/nvidia-settings/+bug/1307236/+attachment/4141174/+files/nvidia-bug-report.log.gz -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to nvidia-settings in Ubuntu. https://bugs.launchpad.net/bugs/1307236 Title: NVidia Issues - blurry text after upgrading from 13.10 to 14.04 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/nvidia-settings/+bug/1307236/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp