Ouch!! If the vehicle hasn't just gone down into kickdown (as when you stamp the throttle) then this could be a clutch slipping in the CD4E box. They are known for cracked clutch drums at 80k+ if abused.
Check the transmission oil for level and also colour. If it's discoloured and burned then I would suspect a box fault.
Try the manual gear positions 1-2-3 to see if it's an electrical fault or mechanical.
Sorry cannot be of much more help as it's difficult to remote diagnose a gearbox fault.
Pichacker, October 2009
