Resolving a noisy bed problem / Silence your squeaky bed

I searched for solutions out there and found advices like
- tightening screws
- lubricating connections

and many other things, some of which don't apply to my bed.

My bed is
- fully metal structure
- mattress is quiet
- the head and bottom of the bed are independent parts and contain the legs, so it is a 3 piece structure
- the horizontal part falls on some cavities on head/bottom boards, and are tightened with screws/bolts

I tried several of the advices out there that apply to my case, but it did not resolve the problem.


I though on applying a more flexible solution, one like the ones that work in everyday life.

If two parts have to be together, and by being together and linked hardly (screws) they create conflict (noise), then you have to loose the connection so each one has room to move around (= loose the screws, which in my case I removed them completely as there is no risk of the bed falling apart). Additionally, if two have to be together and that is "too much contact" for each other, think that together doesn't mean they have to be in permanent contact all the time. So I surrounded the section of the horizontal part that introduces itself on the cavities (displayed as a holding hook) of the vertical parts, with foam packaging.

Summary:
The bed is still holding together
There is no hard & tight connection between the pieces, which reduces tension.
The pieces don't touch each other directly, there is a thin layer of foam between them

Result:
It makes no noise at all.

Image of foam: http://www.creative-cardboard-boxes.com/images/foam-wrap.jpg