Look in the owners manual and make sure the suspension is set to factory settings.
Look in this months Bike magazine and check out how to set the suspension sag. That should set your preload both front and rear to the required degree.
If it's still not right you could try making small adjustments to the damping at either end, just one click at a time (you can always go back to standard if you mess it up), or go to someone who can set up suspension in your area.
hooley, you may be like a lot of us on the site and have'nt a clue about suspension, best take your bike to the professionals and get it done right. You will notice the difference.
Ah, now if it's THAT bike you're on about (instead of the 748 in your original avatar). Just take an ordinary household pin and stab it all over. That'll stop the bugger bouncing.