Gearbox issue, delay in power hitting wheels, unusual revving

Hi guys,

I'm in Australia and have a 2004 Magna sedan automatic. Two days ago it started having an issue, where if you press the accelerator, the revs climb but it take maybe 1-1.5 seconds for there to be a response from the wheels. If you put the revs up to say 3000 then after the delay, it kicks in hard. At idle the revs are fluttering between 1000-1500 all the time, and it seems to take longer for the gear change to happen. It's my fiorst automatic so I've no knowledge, and any help would be really appreciated. Great work on the site too, you're doing a great service.

Many thanks,

Keith B