Multitronic fault

Having owned a lot of audi,s and never had any serious faults I have a dilema with my current one which is an A6 2.5 tdi avant on a 2002 plate. Its got just over 120k miles on the clock with full Audi service history. It seems a little slugish at engaging gear on inital pull away and between 1500 and 1650 rpm jumps between gears, there is also a judder between 3rd and 4th.  Now tomorrow it is booked into my local audi dealer for a service on the gearbox (£150.00) as it hasn't had one since 61k which is when it also had the mod clutch unit (7 plates instead of 6) and so it has only covered 60k on the new clutch.  Didn't pick these faults up on the test drive as they only developed about 2 weeks after purchasing the car.  Now I've read the other multitronic faults on this site and it does seems that the lack of service on the gearbox may be the fault - and I hope it is.  Now despite it having full audi serivce history it does seems that audi have failed to do the 100k service on the gearbox. I'm also sure that it is slipping but at 2600 rpm it takes off well and zips upto 100 effortlessly.  I have had clutch slippage in the past on fords and it seems to get worse the higher up the rev  range you get but that is not the case here, there are no error codes at all.  Any ideas with regard to the slippage as my knowledge of these gearboxes is very limited.

As an addition where do I get the special tool part :-



ATF charging device for CVT gearboxes
ASE40910000000
VAS 5162 
1


from for future use???
TIA