BMW 323i e36 , feels sluggish

[TSSD]

I have a automatic e36, 98 bmw 323i, it has been regularly serviced by bmw.
the problem is that the car has felt a bit sluggish recently, it feels slower when going from 0-30 mph , as if it is missing a gear or you feel like your starting in 2nd gear. I can press the accelerator pedal nearly floor down and i didnt use to have to do this to gain speed. There is no problem with the on board computer car status, and nothing on the dash display, to say there is a problem. Is this a transmission problem or as BMW told me, it could be a 'chip' that needs changing.
Has anyone experienced this type of problem?