Guys,
Thanks for all the advice! Lots of good ideas here. I think I did have the mast sort of vertical, it certainly wasn't leant over much, here's what I think was happening:
1) Trying the flip too late.
2) Leaning my weight outboard, due to the pull of a partly loaded up sail, so when I try the flip I fall off. This is related to 1.
Practice, practice, for lessons don't be late;
Then you'll windsurf till you're 88.
Haircut: Where would I hire it from? I've looked in all the local video shops for anything related to windsurfing, and there's nothing. Maybe we could all set up a windsurfing material library, with DVD's, videos, books, able to be rented out or loaned? Meh, too much effort.
MikeyS: That's a good idea. Next time I'll look for a small wave.
Thanks to everyone, I don't know what I'd do without this forum