Richard, sounds like your neck joint is a bit loose. Lay the bass on its side and push gently up and down on the neck while holding the body steady. If you see any movement around the area where the neck meets the body, you need to get it glued up.

Arnold, thank you.
Yes, this makes good sense. I did it to the endpin, but never thought to do it to the neck, where I can make the bass creak.
It's early morning here and people (wife and daughter) are still sleeping, but I'll try this later this morning - no sense in waking the women folk before time.
There's something else I forgot to mention. I have a violin shaped bass. I noticed ages ago that the violin shape pointy bit at the top of the cut away (front of bass - where I tend to lift the bass from) is not glued properly. Maybe the front is badly glued near the neck too? Anyway, I'll get it to a local luthier soon. Thanks again Arnold.

Well, I just did a neck test (thanks again Arnold) and no creak from there. I tried to upload some pictures I took, but I really suck at computer stuff - sorry.
Normally these pictures upload.
I don't really think that the unglued corner is causing the creak though.