I just upgraded to Ubuntu 15.04 and can no longer reproduce this bug. My xorg package is 1:7.7+7ubuntu4. As far as I know the upgrade is the only change I've made to my desktop since the last time I could reproduce the bug.
I hope this new information is helpful. I'd still be happy to help out with further testing or by providing more information about my hardware and software.
I just upgraded to Ubuntu 15.04 and can no longer reproduce this bug. My xorg package is 1:7.7+7ubuntu4. As far as I know the upgrade is the only change I've made to my desktop since the last time I could reproduce the bug.
I hope this new information is helpful. I'd still be happy to help out with further testing or by providing more information about my hardware and software.