First and foremost, let me apologize in advance as I'm going to royally screw up some terms that are probably 2nd nature to you all and even if I continue to hear these terms for 20 years to come, I will probably still address them in my own language - as anyone who has known me for some time can attest.

So, on with my question.
I have an ENO doublenest and like 12 foot or so of webbing (my hubby did all the research from this here board, so I know he got the good info!). It's not the stretchy webbing, it's the good stuff (I can't remember what stretches, nylon?)

Anyway, we hung the hammock up using the webbing and 3 rings. One daddy ring (the big one) which is attached to one end of our webbing and two babies (a tad smaller). After we wrapped the webbing around the tree we ran it through the daddy ring and pulled tight. Then the long dangling end of the webbing went through the hookthingy on the hammock and back through the two baby rings.

The two baby rings and the webbing were threaded like a belt so it pulled tight. Hubby make a slipknot above the rings and everything holds fine.

Here's the problem/question:
If we don't put the slipknot, it slides and will drop me on my butt. Is this normal? Shouldn't the two rings grip the webbing enough (like a belt) to keep it in place even without the knot? Shouldn't the knot just be for added security?

I'm sorry for my real lack of terminology, my hubby probably should have posted but I'm at work and really kind of wanted to know. So if you can remotely understand what I'm saying, I'd greatly appreciate any advice. (or I'll just bug those of you going to the hang out in hot springs!)