I have never planned a route with the computer software so I'm afraid I can't help you with that one, but as supramat says, sometimes I put a route into my tomtom and change it if i want to avoid certain points etc the day before, switch it on the next day and it is all still there.

The latest version of software is far better than the old version, so make sure you have the latest one uploaded.

Map updates cost £50 which is a rediculous amount of money, can almost get a new sat nav for that!!