I'm with you David. Will it start or won't it is about as complicated as I can cope with. Having read this thread I've just checked if my 996 will turn it over and it does. Before Christmas, it was dead. I first put it on a full size (i.e. not an Optimate) battery charger as the battery was only about 9 months old. That got it going and since then it's been on an Optimate. Started up a treat just now.
Might sound stupid but do you know there's a little button on the throttle that gives it (I'm assuming) a touch of choke to start it up. I only discovered this about a year ago so pardon me if I'm teaching you to suck eggs. Let it run for 2 or 3 minutes then rev the throttle and the button will click off.