Don't know if it's anything to do with your prob Welung -- but I have recently been diagnosed (guessed at -- in the absence of any other explanation!) with M.E. ..... When I am about to have a bad spell my lower back is a killer !!! If I rest up as I am supposed to (not all day in bed type of rest -- but "zoning out" for 10 mins or so every hour) it eases considerably (never goes though
) It is a sort of barometer to my general well-being!
Unlike your Temazipam though, I find the diazepam zonks me out really well. Temazepam (sp) is more often prescribed for sleep problems, whereas the diazepam I am on is more for muscle spasms.
I also take co-codamol together with Iboprufen during the day.
Have a word with your GP ---- one of the big probs with back pain is the muscular spasms it causes -- which in turn make the pain worse -- viscious circle time!!!! So it might be worth trying a muscle relaxant as opposed to a sleep inducer ( which isn't working!!!).
Best of luck with it mate. 
The Bells does that
Like I said my Doc is a bit of a dick so gave me Tomazapan to help me sleep rather than treat the symptoms. It would be a great help if he could speak english 
Get a second opinion Welung as it seem now that most GP's prescribe meds all too readily rather than explore the problem. I think also that alcohol is a stimulant so that may not help you at bed time.
If you try having a carbs rich meal (like pasta, rice, spuds etc,) in the evening at your usual time - but watch the quantity, you'll find that sleep comes much more readily. Also if you have a snack just before bed say of bananas on toast, hot milk or some chamomile tea - no really- these will help you to sleep.
The liver has to process everything that we intake during the course of the day and when it gets overloaded the viscious circle begins and the entire system is stressed - leading to complaints such insommnia
In the end Welung it seems that we now have to take charge of our own health and wellbeing as it is apparent that a lot of GP's are either incompetent or unwilling to do what they should be doing. At the very least talk to another GP. It might also be an idea to google sleep deprivation clinics, if there's one near you, that's another potential solution.
Best of luck
