Comment 11 for bug 1386473

The 3.16.5, 3.16.6 and 3.16.7 upstream updates are now in the Ubuntu 3.16.0-25.33 kernel which is available in the -proposed repository.

Would it be possible for you to test this latest kernel and post back if it resolves this bug?
See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed.