Ok, I didn't go about this too scientifically, didn't record the combinations I tried, but I tried to get this damned thing going with 2 or 3 libraries, to no avail. Then I spotted this link to Stuart Lewis earlier in this thread and tried it. Still no luck. It's the one with no libraries: I thought I'd try that, reducing the number of places for errors.
So then I tried the sketch his code linked to and was based on, namely the Hello World sketch in the Playground and Voila! it worked.
I thought, ok, let's go back a step and try Stuart's again and trouble shoot a bit... no trouble to shoot, it worked all of a sudden.
So are these displays a bit temperamental? Did I have persistent loose breadboard pins which a bump set right? I have no idea... At least I know the display works.
But now I'm going to switch to a library-based method, since that's a better way innit? One thing I will do though, is use the breadboard / LCD setup that I currently have, not going to change the hardware at all, and just set the pins in the sketch. Try and disrupt things as little as possible.
Jings, this is frustrating, butSaturday arvie not totally wasted.....