Comment 36 for bug 1331654

@Cedric, currently, the officially released kernel version in Ubuntu Trusty is linux-generic (3.13.0.35.42): http://packages.ubuntu.com/trusty-updates/kernel/

I can confirm that this version is finally fixed wrt the suspend/resume bug. Make sure your update sources for kernel are nominal, e.g. check if you're using trusty-proposed, if so try disabling them and downgrading to the officially released kernel.