I am sure I have seen a thread on here somewhere but this from a different site seems to have the Freelander answer.

Intermitant wiper parking problem - Freelander Forum - LR4x4 - The Land Rover Forum

And by the way - Mine has just passed it's MOT with an advisory regarding the wiper parking.:bounce:

The answer on this one was that the motor drive shaft had slipped in relation to the first arm in the linkage of the wiper mechanism, putting the park position of the wipers out of phase with the park position of the motor.

Disconnecting the linkage from the motor and moving the position of the linkage slightly before reattaching the first arm back to the motor drive shaft solved the problem. Nothing wrong with the motor or the parking switch in/on the motor.

(It wasn't quite that simple, needing a couple of goes to get it right, but that was the basic answer.)

As the car still hasn't been for its MOT I didn't find out if it was an advisory or a fail.