Well as i've got the manual in front of me I thought I might help you out a bit more.
There are two buttons on the selector lever, the one on the side is for selecting R or 2 (but not moving between position 1 and 2) it also is used to move out of P (while depressing the brake pedal too) and the one under the grip is to select or de-select overdrive (an indication will show in the trip meter section on dash) (if the gear-box is changing up and down from 4th and 3rd a lot then de-select overdrive)
[max revs in N and P is 4100]
ECONOMY MODE {E}
In this mode, the transmission changes to a high gear earlier and to low gear later. Use for normal driving.
SPORT MODE {S}
High gear selection is delayed so that the engines power is fully used. Downshifting takes place at higher engine speeds, e.g. In a quick overtaking manoeuvre. The control light illuminates in the trip meter window when sport mode is selected.
If {!} shows in the trip meter display then the auto-gear box has a fault.
The green button Phil refered to is situated under the passenger side of the center console (if memory serves me correctly) and is used in emergency occasions to de-select P mechanicaly (in the event of power failure)