Hi Phil, I'd say you have the original (known to fail a lot) SPU - a search here will return a lot of results. If I remember rightly you bought the red 750 that was new but been sat in the show room for a little while ? If so go beat Phil up and make him sort it out - if they still have the black 750 there they can try the spu off that one and find out in about 10 mins if that's the problem.
If you don't want to involve the dealer, contact me and we can try my spu - I'm 5 minutes of the F3, Calga exit.
And you DON'T have to have the bike serviced by an MV dealer to maintain the warranty...
Mods - mirrors (so you can see the guys with the flashing roof rack behind you) , foot pegs (so your feet don't slip off all the time), get rid of cat (a little more tunes from the exhaust, less heat), powercommander (less fuel, better running and a bit more go).