how can i fix problem on corsa 1.4i automatic sport mode?

when cold starting, sports mode flashes on instrument pannel and will not pull away without using alot of revs, so have to drive it manualy until it has warmed up, then i have to switch off completely and restart engine, and then it drives perfectley, sometimes i have to switch off and restart two or three times before it works ok, nearly always when cold, very rarely when warm,