Firstly i'd like to say thankyou for the reply, i'm very grateful to get someone else's opinion.

I quite often visit a chiro but it doesn't seem to do much (except give me a headache).

Although a while ago he worked on my back and neck and I felt great, I was stronger than I had been in ages, but it only lasted about 2 weeks.

One thing I have noticed is, when they twist me over, (they push my leg down and push my shoulder back, twisting the spine) it feels extremely tight, but it never seems to go "crack", just an observation.
Also I notice it if i'm sitting down and twist to the right to pick something up beside/behind me it pinches.

What does an osteopath do?

Btw I got the result of my ct scan and it said the following, I quote:

"evaluation of the l3/4 l4/5 and l5/s1 discs have been undertaken.
Contour of the l3/4 disc is normal.
Both the l4/5 and l5/s1 discs show flattened posterior margins but no prolapse is evident.
Spinal canal dimensions are normal at all levels no foraminal stenosis or neural arch defect shown."
still doesn't really explain why my lower back hurts.

I got a copy of the ct scans and have since put them on my computer, please let me know if they will assist in any way.
At this stage i'm willing to try anything (well maybe not aything, I am married you know, ha)
thanks again for all you help