Dell XPS 13 Ubuntu (l322x) gets stuck asleep.

I'm having problems with my l322x Ubuntu release XPS 13. When left to go to sleep, put to sleep or closing the lid to sleep it becomes impossible to wake properly, throttling up the fans and turning on the display and keyboard light but showing only a black screen. It also does not respond to the hard power off signal (holding the power button) even when pressed for upwards of 30 seconds. The only solution is to unplug and wait for the battery to run out, at which point it boots normally. This has happened increasingly over the past 2 months.

I will put system information here as soon as I can get it. But I can say there is a windows 7 partition installed, although the problem does not occur when that partition is booted to. I use the GRUB boot loader from Ubuntu, if that makes any difference.