A3 automatic
 

Hi
Anyone any ideas on a fault in an A3 automatic.
Sometimes on take off with the gear stick in the D position there is no response,car does not move,shifting it out to N or P and then back again to D and it will move off fine.
This only happens on the odd occassion and otherwise the car runs and sound fine.
The full model spec is a 2005 2.0tdi Dsg

Thanks